diff --git a/lib/vendor/box/spout/src/Spout/Common/Entity/Cell.php b/lib/vendor/box/spout/src/Spout/Common/Entity/Cell.php
index 174831c29a..db87c3a9b1 100644
--- a/lib/vendor/box/spout/src/Spout/Common/Entity/Cell.php
+++ b/lib/vendor/box/spout/src/Spout/Common/Entity/Cell.php
@@ -68,7 +68,7 @@ class Cell
      * @param mixed|null $value
      * @param Style|null $style
      */
-    public function __construct($value, Style $style = null)
+    public function __construct($value, ?Style $style = null)
     {
         $this->setValue($value);
         $this->setStyle($style);
diff --git a/lib/vendor/box/spout/src/Spout/Reader/Exception/InvalidValueException.php b/lib/vendor/box/spout/src/Spout/Reader/Exception/InvalidValueException.php
index 6ed0b6d0e0..216c754995 100644
--- a/lib/vendor/box/spout/src/Spout/Reader/Exception/InvalidValueException.php
+++ b/lib/vendor/box/spout/src/Spout/Reader/Exception/InvalidValueException.php
@@ -18,7 +18,7 @@ class InvalidValueException extends ReaderException
      * @param int $code
      * @param Throwable|null $previous
      */
-    public function __construct($invalidValue, $message = '', $code = 0, Throwable $previous = null)
+    public function __construct($invalidValue, $message = '', $code = 0, ?Throwable $previous = null)
     {
         $this->invalidValue = $invalidValue;
         parent::__construct($message, $code, $previous);
diff --git a/lib/vendor/box/spout/src/Spout/Writer/Common/Creator/WriterEntityFactory.php b/lib/vendor/box/spout/src/Spout/Writer/Common/Creator/WriterEntityFactory.php
index 8e43c31e38..cd38f7da35 100644
--- a/lib/vendor/box/spout/src/Spout/Writer/Common/Creator/WriterEntityFactory.php
+++ b/lib/vendor/box/spout/src/Spout/Writer/Common/Creator/WriterEntityFactory.php
@@ -86,7 +86,7 @@ class WriterEntityFactory
      * @param Style|null $rowStyle
      * @return Row
      */
-    public static function createRow(array $cells = [], Style $rowStyle = null)
+    public static function createRow(array $cells = [], ?Style $rowStyle = null)
     {
         return new Row($cells, $rowStyle);
     }
@@ -96,7 +96,7 @@ class WriterEntityFactory
      * @param Style|null $rowStyle
      * @return Row
      */
-    public static function createRowFromArray(array $cellValues = [], Style $rowStyle = null)
+    public static function createRowFromArray(array $cellValues = [], ?Style $rowStyle = null)
     {
         $cells = \array_map(function ($cellValue) {
             return new Cell($cellValue);
@@ -110,7 +110,7 @@ class WriterEntityFactory
      * @param Style|null $cellStyle
      * @return Cell
      */
-    public static function createCell($cellValue, Style $cellStyle = null)
+    public static function createCell($cellValue, ?Style $cellStyle = null)
     {
         return new Cell($cellValue, $cellStyle);
     }
diff --git a/lib/vendor/dragonmantank/cron-expression/src/Cron/CronExpression.php b/lib/vendor/dragonmantank/cron-expression/src/Cron/CronExpression.php
index 594b435825..db7d36c266 100644
--- a/lib/vendor/dragonmantank/cron-expression/src/Cron/CronExpression.php
+++ b/lib/vendor/dragonmantank/cron-expression/src/Cron/CronExpression.php
@@ -67,7 +67,7 @@ class CronExpression
      *
      * @return CronExpression
      */
-    public static function factory($expression, FieldFactory $fieldFactory = null)
+    public static function factory($expression, ?FieldFactory $fieldFactory = null)
     {
         $mappings = array(
             '@yearly' => '0 0 1 1 *',
@@ -110,7 +110,7 @@ class CronExpression
      * @param string       $expression   CRON expression (e.g. '8 * * * *')
      * @param FieldFactory|null $fieldFactory Factory to create cron fields
      */
-    public function __construct($expression, FieldFactory $fieldFactory = null)
+    public function __construct($expression, ?FieldFactory $fieldFactory = null)
     {
         $this->fieldFactory = $fieldFactory;
         $this->setExpression($expression);
diff --git a/lib/vendor/erusev/parsedown/Parsedown.php b/lib/vendor/erusev/parsedown/Parsedown.php
index 0d96df3da5..429e8d58da 100644
--- a/lib/vendor/erusev/parsedown/Parsedown.php
+++ b/lib/vendor/erusev/parsedown/Parsedown.php
@@ -713,7 +713,7 @@ class Parsedown
     #
     # Setext
 
-    protected function blockSetextHeader($Line, array $Block = null)
+    protected function blockSetextHeader($Line, ?array $Block = null)
     {
         if ( ! isset($Block) or isset($Block['type']) or isset($Block['interrupted']))
         {
@@ -851,7 +851,7 @@ class Parsedown
     #
     # Table
 
-    protected function blockTable($Line, array $Block = null)
+    protected function blockTable($Line, ?array $Block = null)
     {
         if ( ! isset($Block) or isset($Block['type']) or isset($Block['interrupted']))
         {
diff --git a/lib/vendor/mobiledetect/mobiledetectlib/Mobile_Detect.php b/lib/vendor/mobiledetect/mobiledetectlib/Mobile_Detect.php
index 55a8823719..69777f3f9d 100644
--- a/lib/vendor/mobiledetect/mobiledetectlib/Mobile_Detect.php
+++ b/lib/vendor/mobiledetect/mobiledetectlib/Mobile_Detect.php
@@ -886,7 +886,7 @@ class Mobile_Detect
      *                          from the $headers array instead.
      */
     public function __construct(
-        array $headers = null,
+        ?array $headers = null,
         $userAgent = null
     ) {
         $this->setHttpHeaders($headers);
diff --git a/lib/vendor/phpoffice/phpspreadsheet/src/PhpSpreadsheet/Calculation/Calculation.php b/lib/vendor/phpoffice/phpspreadsheet/src/PhpSpreadsheet/Calculation/Calculation.php
index ae06d654dc..897b9222cc 100644
--- a/lib/vendor/phpoffice/phpspreadsheet/src/PhpSpreadsheet/Calculation/Calculation.php
+++ b/lib/vendor/phpoffice/phpspreadsheet/src/PhpSpreadsheet/Calculation/Calculation.php
@@ -2200,7 +2200,7 @@ class Calculation
         ],
     ];
 
-    public function __construct(Spreadsheet $spreadsheet = null)
+    public function __construct(?Spreadsheet $spreadsheet = null)
     {
         $this->delta = 1 * pow(10, 0 - ini_get('precision'));
 
@@ -2228,7 +2228,7 @@ class Calculation
      *
      * @return Calculation
      */
-    public static function getInstance(Spreadsheet $spreadsheet = null)
+    public static function getInstance(?Spreadsheet $spreadsheet = null)
     {
         if ($spreadsheet !== null) {
             $instance = $spreadsheet->getCalculationEngine();
@@ -2693,7 +2693,7 @@ class Calculation
      *
      * @return mixed
      */
-    public function calculate(Cell $pCell = null)
+    public function calculate(?Cell $pCell = null)
     {
         try {
             return $this->calculateCellValue($pCell);
@@ -2712,7 +2712,7 @@ class Calculation
      *
      * @return mixed
      */
-    public function calculateCellValue(Cell $pCell = null, $resetLog = true)
+    public function calculateCellValue(?Cell $pCell = null, $resetLog = true)
     {
         if ($pCell === null) {
             return null;
@@ -2816,7 +2816,7 @@ class Calculation
      *
      * @return mixed
      */
-    public function calculateFormula($formula, $cellID = null, Cell $pCell = null)
+    public function calculateFormula($formula, $cellID = null, ?Cell $pCell = null)
     {
         //    Initialise the logging settings
         $this->formulaError = null;
@@ -2892,7 +2892,7 @@ class Calculation
      *
      * @return mixed
      */
-    public function _calculateFormulaValue($formula, $cellID = null, Cell $pCell = null)
+    public function _calculateFormulaValue($formula, $cellID = null, ?Cell $pCell = null)
     {
         $cellValue = null;
 
@@ -3294,7 +3294,7 @@ class Calculation
      *
      * @return bool
      */
-    private function _parseFormula($formula, Cell $pCell = null)
+    private function _parseFormula($formula, ?Cell $pCell = null)
     {
         if (($formula = $this->convertMatrixReferences(trim($formula))) === false) {
             return false;
@@ -3628,7 +3628,7 @@ class Calculation
      *
      * @return bool
      */
-    private function processTokenStack($tokens, $cellID = null, Cell $pCell = null)
+    private function processTokenStack($tokens, $cellID = null, ?Cell $pCell = null)
     {
         if ($tokens == false) {
             return false;
@@ -4304,7 +4304,7 @@ class Calculation
      *
      * @return mixed Array of values in range if range contains more than one element. Otherwise, a single value is returned.
      */
-    public function extractCellRange(&$pRange = 'A1', Worksheet $pSheet = null, $resetLog = true)
+    public function extractCellRange(&$pRange = 'A1', ?Worksheet $pSheet = null, $resetLog = true)
     {
         // Return value
         $returnValue = [];
@@ -4357,7 +4357,7 @@ class Calculation
      *
      * @return mixed Array of values in range if range contains more than one element. Otherwise, a single value is returned.
      */
-    public function extractNamedRange(&$pRange = 'A1', Worksheet $pSheet = null, $resetLog = true)
+    public function extractNamedRange(&$pRange = 'A1', ?Worksheet $pSheet = null, $resetLog = true)
     {
         // Return value
         $returnValue = [];
@@ -4464,7 +4464,7 @@ class Calculation
      *
      * @return array
      */
-    private function addCellReference(array $args, $passCellReference, $functionCall, Cell $pCell = null)
+    private function addCellReference(array $args, $passCellReference, $functionCall, ?Cell $pCell = null)
     {
         if ($passCellReference) {
             if (is_array($functionCall)) {
diff --git a/lib/vendor/phpoffice/phpspreadsheet/src/PhpSpreadsheet/Calculation/Functions.php b/lib/vendor/phpoffice/phpspreadsheet/src/PhpSpreadsheet/Calculation/Functions.php
index 0a607c702a..d3a58793df 100644
--- a/lib/vendor/phpoffice/phpspreadsheet/src/PhpSpreadsheet/Calculation/Functions.php
+++ b/lib/vendor/phpoffice/phpspreadsheet/src/PhpSpreadsheet/Calculation/Functions.php
@@ -653,7 +653,7 @@ class Functions
      *
      * @return bool|string
      */
-    public static function isFormula($cellReference = '', Cell $pCell = null)
+    public static function isFormula($cellReference = '', ?Cell $pCell = null)
     {
         if ($pCell === null) {
             return self::REF();
diff --git a/lib/vendor/phpoffice/phpspreadsheet/src/PhpSpreadsheet/Calculation/LookupRef.php b/lib/vendor/phpoffice/phpspreadsheet/src/PhpSpreadsheet/Calculation/LookupRef.php
index e6b0f3203f..cb940f2ffb 100644
--- a/lib/vendor/phpoffice/phpspreadsheet/src/PhpSpreadsheet/Calculation/LookupRef.php
+++ b/lib/vendor/phpoffice/phpspreadsheet/src/PhpSpreadsheet/Calculation/LookupRef.php
@@ -238,7 +238,7 @@ class LookupRef
      *
      * @return mixed The value of $displayName (or $linkURL if $displayName was blank)
      */
-    public static function HYPERLINK($linkURL = '', $displayName = null, Cell $pCell = null)
+    public static function HYPERLINK($linkURL = '', $displayName = null, ?Cell $pCell = null)
     {
         $linkURL = ($linkURL === null) ? '' : Functions::flattenSingleValue($linkURL);
         $displayName = ($displayName === null) ? '' : Functions::flattenSingleValue($displayName);
@@ -275,7 +275,7 @@ class LookupRef
      *
      * @todo    Support for the optional a1 parameter introduced in Excel 2010
      */
-    public static function INDIRECT($cellAddress = null, Cell $pCell = null)
+    public static function INDIRECT($cellAddress = null, ?Cell $pCell = null)
     {
         $cellAddress = Functions::flattenSingleValue($cellAddress);
         if ($cellAddress === null || $cellAddress === '') {
@@ -343,7 +343,7 @@ class LookupRef
      *
      * @return string A reference to a cell or range of cells
      */
-    public static function OFFSET($cellAddress = null, $rows = 0, $columns = 0, $height = null, $width = null, Cell $pCell = null)
+    public static function OFFSET($cellAddress = null, $rows = 0, $columns = 0, $height = null, $width = null, ?Cell $pCell = null)
     {
         $rows = Functions::flattenSingleValue($rows);
         $columns = Functions::flattenSingleValue($columns);
@@ -903,7 +903,7 @@ class LookupRef
      *
      * @return string
      */
-    public static function FORMULATEXT($cellReference = '', Cell $pCell = null)
+    public static function FORMULATEXT($cellReference = '', ?Cell $pCell = null)
     {
         if ($pCell === null) {
             return Functions::REF();
diff --git a/lib/vendor/phpoffice/phpspreadsheet/src/PhpSpreadsheet/Cell/Cell.php b/lib/vendor/phpoffice/phpspreadsheet/src/PhpSpreadsheet/Cell/Cell.php
index 813eee4a09..1eba67bd8c 100644
--- a/lib/vendor/phpoffice/phpspreadsheet/src/PhpSpreadsheet/Cell/Cell.php
+++ b/lib/vendor/phpoffice/phpspreadsheet/src/PhpSpreadsheet/Cell/Cell.php
@@ -397,7 +397,7 @@ class Cell
      *
      * @return Cell
      */
-    public function setDataValidation(DataValidation $pDataValidation = null)
+    public function setDataValidation(?DataValidation $pDataValidation = null)
     {
         if (!isset($this->parent)) {
             throw new Exception('Cannot set data validation for cell that is not bound to a worksheet');
@@ -461,7 +461,7 @@ class Cell
      *
      * @return Cell
      */
-    public function setHyperlink(Hyperlink $pHyperlink = null)
+    public function setHyperlink(?Hyperlink $pHyperlink = null)
     {
         if (!isset($this->parent)) {
             throw new Exception('Cannot set hyperlink for cell that is not bound to a worksheet');
diff --git a/lib/vendor/phpoffice/phpspreadsheet/src/PhpSpreadsheet/Chart/Chart.php b/lib/vendor/phpoffice/phpspreadsheet/src/PhpSpreadsheet/Chart/Chart.php
index 3d09a041d5..fd5ccd26d9 100644
--- a/lib/vendor/phpoffice/phpspreadsheet/src/PhpSpreadsheet/Chart/Chart.php
+++ b/lib/vendor/phpoffice/phpspreadsheet/src/PhpSpreadsheet/Chart/Chart.php
@@ -156,7 +156,7 @@ class Chart
      * @param null|GridLines $majorGridlines
      * @param null|GridLines $minorGridlines
      */
-    public function __construct($name, Title $title = null, Legend $legend = null, PlotArea $plotArea = null, $plotVisibleOnly = true, $displayBlanksAs = '0', Title $xAxisLabel = null, Title $yAxisLabel = null, Axis $xAxis = null, Axis $yAxis = null, GridLines $majorGridlines = null, GridLines $minorGridlines = null)
+    public function __construct($name, ?Title $title = null, ?Legend $legend = null, ?PlotArea $plotArea = null, $plotVisibleOnly = true, $displayBlanksAs = '0', ?Title $xAxisLabel = null, ?Title $yAxisLabel = null, ?Axis $xAxis = null, ?Axis $yAxis = null, ?GridLines $majorGridlines = null, ?GridLines $minorGridlines = null)
     {
         $this->name = $name;
         $this->title = $title;
@@ -199,7 +199,7 @@ class Chart
      *
      * @return Chart
      */
-    public function setWorksheet(Worksheet $pValue = null)
+    public function setWorksheet(?Worksheet $pValue = null)
     {
         $this->worksheet = $pValue;
 
diff --git a/lib/vendor/phpoffice/phpspreadsheet/src/PhpSpreadsheet/Chart/Legend.php b/lib/vendor/phpoffice/phpspreadsheet/src/PhpSpreadsheet/Chart/Legend.php
index d077626510..2b46af64f9 100644
--- a/lib/vendor/phpoffice/phpspreadsheet/src/PhpSpreadsheet/Chart/Legend.php
+++ b/lib/vendor/phpoffice/phpspreadsheet/src/PhpSpreadsheet/Chart/Legend.php
@@ -55,7 +55,7 @@ class Legend
      * @param null|Layout $layout
      * @param bool $overlay
      */
-    public function __construct($position = self::POSITION_RIGHT, Layout $layout = null, $overlay = false)
+    public function __construct($position = self::POSITION_RIGHT, ?Layout $layout = null, $overlay = false)
     {
         $this->setPosition($position);
         $this->layout = $layout;
diff --git a/lib/vendor/phpoffice/phpspreadsheet/src/PhpSpreadsheet/Chart/PlotArea.php b/lib/vendor/phpoffice/phpspreadsheet/src/PhpSpreadsheet/Chart/PlotArea.php
index b98c638df7..9076c5b611 100644
--- a/lib/vendor/phpoffice/phpspreadsheet/src/PhpSpreadsheet/Chart/PlotArea.php
+++ b/lib/vendor/phpoffice/phpspreadsheet/src/PhpSpreadsheet/Chart/PlotArea.php
@@ -26,7 +26,7 @@ class PlotArea
      * @param null|Layout $layout
      * @param DataSeries[] $plotSeries
      */
-    public function __construct(Layout $layout = null, array $plotSeries = [])
+    public function __construct(?Layout $layout = null, array $plotSeries = [])
     {
         $this->layout = $layout;
         $this->plotSeries = $plotSeries;
diff --git a/lib/vendor/phpoffice/phpspreadsheet/src/PhpSpreadsheet/Chart/Title.php b/lib/vendor/phpoffice/phpspreadsheet/src/PhpSpreadsheet/Chart/Title.php
index f53c6b37bd..339afa53e6 100644
--- a/lib/vendor/phpoffice/phpspreadsheet/src/PhpSpreadsheet/Chart/Title.php
+++ b/lib/vendor/phpoffice/phpspreadsheet/src/PhpSpreadsheet/Chart/Title.php
@@ -24,7 +24,7 @@ class Title
      * @param null|mixed $caption
      * @param null|Layout $layout
      */
-    public function __construct($caption = null, Layout $layout = null)
+    public function __construct($caption = null, ?Layout $layout = null)
     {
         $this->caption = $caption;
         $this->layout = $layout;
diff --git a/lib/vendor/phpoffice/phpspreadsheet/src/PhpSpreadsheet/HashTable.php b/lib/vendor/phpoffice/phpspreadsheet/src/PhpSpreadsheet/HashTable.php
index 4e8f0a5c91..6dc713e194 100644
--- a/lib/vendor/phpoffice/phpspreadsheet/src/PhpSpreadsheet/HashTable.php
+++ b/lib/vendor/phpoffice/phpspreadsheet/src/PhpSpreadsheet/HashTable.php
@@ -40,7 +40,7 @@ class HashTable
      *
      * @throws Exception
      */
-    public function addFromSource(array $pSource = null)
+    public function addFromSource(?array $pSource = null)
     {
         // Check if an array was passed
         if ($pSource == null) {
diff --git a/lib/vendor/phpoffice/phpspreadsheet/src/PhpSpreadsheet/NamedRange.php b/lib/vendor/phpoffice/phpspreadsheet/src/PhpSpreadsheet/NamedRange.php
index 1f94d5a4ed..8570897a7f 100644
--- a/lib/vendor/phpoffice/phpspreadsheet/src/PhpSpreadsheet/NamedRange.php
+++ b/lib/vendor/phpoffice/phpspreadsheet/src/PhpSpreadsheet/NamedRange.php
@@ -125,7 +125,7 @@ class NamedRange
      *
      * @return NamedRange
      */
-    public function setWorksheet(Worksheet $value = null)
+    public function setWorksheet(?Worksheet $value = null)
     {
         if ($value !== null) {
             $this->worksheet = $value;
@@ -202,7 +202,7 @@ class NamedRange
      *
      * @return NamedRange
      */
-    public function setScope(Worksheet $value = null)
+    public function setScope(?Worksheet $value = null)
     {
         $this->scope = $value;
         $this->localOnly = $value != null;
diff --git a/lib/vendor/phpoffice/phpspreadsheet/src/PhpSpreadsheet/Reader/Xlsx/ColumnAndRowAttributes.php b/lib/vendor/phpoffice/phpspreadsheet/src/PhpSpreadsheet/Reader/Xlsx/ColumnAndRowAttributes.php
index e901d99048..7a564d96a2 100644
--- a/lib/vendor/phpoffice/phpspreadsheet/src/PhpSpreadsheet/Reader/Xlsx/ColumnAndRowAttributes.php
+++ b/lib/vendor/phpoffice/phpspreadsheet/src/PhpSpreadsheet/Reader/Xlsx/ColumnAndRowAttributes.php
@@ -12,7 +12,7 @@ class ColumnAndRowAttributes extends BaseParserClass
 
     private $worksheetXml;
 
-    public function __construct(Worksheet $workSheet, \SimpleXMLElement $worksheetXml = null)
+    public function __construct(Worksheet $workSheet, ?\SimpleXMLElement $worksheetXml = null)
     {
         $this->worksheet = $workSheet;
         $this->worksheetXml = $worksheetXml;
@@ -74,7 +74,7 @@ class ColumnAndRowAttributes extends BaseParserClass
      * @param IReadFilter $readFilter
      * @param bool $readDataOnly
      */
-    public function load(IReadFilter $readFilter = null, $readDataOnly = false)
+    public function load(?IReadFilter $readFilter = null, $readDataOnly = false)
     {
         if ($this->worksheetXml === null) {
             return;
diff --git a/lib/vendor/phpoffice/phpspreadsheet/src/PhpSpreadsheet/Reader/Xlsx/PageSetup.php b/lib/vendor/phpoffice/phpspreadsheet/src/PhpSpreadsheet/Reader/Xlsx/PageSetup.php
index 6f286769c0..10c4c58d15 100644
--- a/lib/vendor/phpoffice/phpspreadsheet/src/PhpSpreadsheet/Reader/Xlsx/PageSetup.php
+++ b/lib/vendor/phpoffice/phpspreadsheet/src/PhpSpreadsheet/Reader/Xlsx/PageSetup.php
@@ -11,7 +11,7 @@ class PageSetup extends BaseParserClass
 
     private $worksheetXml;
 
-    public function __construct(Worksheet $workSheet, \SimpleXMLElement $worksheetXml = null)
+    public function __construct(Worksheet $workSheet, ?\SimpleXMLElement $worksheetXml = null)
     {
         $this->worksheet = $workSheet;
         $this->worksheetXml = $worksheetXml;
diff --git a/lib/vendor/phpoffice/phpspreadsheet/src/PhpSpreadsheet/Reader/Xlsx/SheetViewOptions.php b/lib/vendor/phpoffice/phpspreadsheet/src/PhpSpreadsheet/Reader/Xlsx/SheetViewOptions.php
index eb61a5d306..0621f54d44 100644
--- a/lib/vendor/phpoffice/phpspreadsheet/src/PhpSpreadsheet/Reader/Xlsx/SheetViewOptions.php
+++ b/lib/vendor/phpoffice/phpspreadsheet/src/PhpSpreadsheet/Reader/Xlsx/SheetViewOptions.php
@@ -10,7 +10,7 @@ class SheetViewOptions extends BaseParserClass
 
     private $worksheetXml;
 
-    public function __construct(Worksheet $workSheet, \SimpleXMLElement $worksheetXml = null)
+    public function __construct(Worksheet $workSheet, ?\SimpleXMLElement $worksheetXml = null)
     {
         $this->worksheet = $workSheet;
         $this->worksheetXml = $worksheetXml;
diff --git a/lib/vendor/phpoffice/phpspreadsheet/src/PhpSpreadsheet/Reader/Xlsx/Styles.php b/lib/vendor/phpoffice/phpspreadsheet/src/PhpSpreadsheet/Reader/Xlsx/Styles.php
index d3edaef7b3..6d77d7c242 100644
--- a/lib/vendor/phpoffice/phpspreadsheet/src/PhpSpreadsheet/Reader/Xlsx/Styles.php
+++ b/lib/vendor/phpoffice/phpspreadsheet/src/PhpSpreadsheet/Reader/Xlsx/Styles.php
@@ -31,7 +31,7 @@ class Styles extends BaseParserClass
         $this->styleXml = $styleXml;
     }
 
-    public function setStyleBaseData(Theme $theme = null, $styles = [], $cellStyles = [])
+    public function setStyleBaseData(?Theme $theme = null, $styles = [], $cellStyles = [])
     {
         self::$theme = $theme;
         $this->styles = $styles;
diff --git a/lib/vendor/phpoffice/phpspreadsheet/src/PhpSpreadsheet/RichText/RichText.php b/lib/vendor/phpoffice/phpspreadsheet/src/PhpSpreadsheet/RichText/RichText.php
index 76a04d549f..874e56b33e 100644
--- a/lib/vendor/phpoffice/phpspreadsheet/src/PhpSpreadsheet/RichText/RichText.php
+++ b/lib/vendor/phpoffice/phpspreadsheet/src/PhpSpreadsheet/RichText/RichText.php
@@ -23,7 +23,7 @@ class RichText implements IComparable
      *
      * @throws Exception
      */
-    public function __construct(Cell $pCell = null)
+    public function __construct(?Cell $pCell = null)
     {
         // Initialise variables
         $this->richTextElements = [];
diff --git a/lib/vendor/phpoffice/phpspreadsheet/src/PhpSpreadsheet/RichText/Run.php b/lib/vendor/phpoffice/phpspreadsheet/src/PhpSpreadsheet/RichText/Run.php
index b4996235f3..03c155e3d6 100644
--- a/lib/vendor/phpoffice/phpspreadsheet/src/PhpSpreadsheet/RichText/Run.php
+++ b/lib/vendor/phpoffice/phpspreadsheet/src/PhpSpreadsheet/RichText/Run.php
@@ -42,7 +42,7 @@ class Run extends TextElement implements ITextElement
      *
      * @return ITextElement
      */
-    public function setFont(Font $pFont = null)
+    public function setFont(?Font $pFont = null)
     {
         $this->font = $pFont;
 
diff --git a/lib/vendor/phpoffice/phpspreadsheet/src/PhpSpreadsheet/Shared/Font.php b/lib/vendor/phpoffice/phpspreadsheet/src/PhpSpreadsheet/Shared/Font.php
index 8abcef2e19..bf7662ad2f 100644
--- a/lib/vendor/phpoffice/phpspreadsheet/src/PhpSpreadsheet/Shared/Font.php
+++ b/lib/vendor/phpoffice/phpspreadsheet/src/PhpSpreadsheet/Shared/Font.php
@@ -223,7 +223,7 @@ class Font
      *
      * @return int Column width
      */
-    public static function calculateColumnWidth(\PhpOffice\PhpSpreadsheet\Style\Font $font, $cellText = '', $rotation = 0, \PhpOffice\PhpSpreadsheet\Style\Font $defaultFont = null)
+    public static function calculateColumnWidth(\PhpOffice\PhpSpreadsheet\Style\Font $font, $cellText = '', $rotation = 0, ?\PhpOffice\PhpSpreadsheet\Style\Font $defaultFont = null)
     {
         // If it is rich text, use plain text
         if ($cellText instanceof RichText) {
diff --git a/lib/vendor/phpoffice/phpspreadsheet/src/PhpSpreadsheet/Spreadsheet.php b/lib/vendor/phpoffice/phpspreadsheet/src/PhpSpreadsheet/Spreadsheet.php
index 8eadcbe8b1..1c77fe56be 100644
--- a/lib/vendor/phpoffice/phpspreadsheet/src/PhpSpreadsheet/Spreadsheet.php
+++ b/lib/vendor/phpoffice/phpspreadsheet/src/PhpSpreadsheet/Spreadsheet.php
@@ -930,7 +930,7 @@ class Spreadsheet
      *
      * @return null|NamedRange
      */
-    public function getNamedRange($namedRange, Worksheet $pSheet = null)
+    public function getNamedRange($namedRange, ?Worksheet $pSheet = null)
     {
         $returnValue = null;
 
@@ -957,7 +957,7 @@ class Spreadsheet
      *
      * @return Spreadsheet
      */
-    public function removeNamedRange($namedRange, Worksheet $pSheet = null)
+    public function removeNamedRange($namedRange, ?Worksheet $pSheet = null)
     {
         if ($pSheet === null) {
             if (isset($this->namedRanges[$namedRange])) {
diff --git a/lib/vendor/phpoffice/phpspreadsheet/src/PhpSpreadsheet/Style/Conditional.php b/lib/vendor/phpoffice/phpspreadsheet/src/PhpSpreadsheet/Style/Conditional.php
index 91a000dba4..2cbf10690d 100644
--- a/lib/vendor/phpoffice/phpspreadsheet/src/PhpSpreadsheet/Style/Conditional.php
+++ b/lib/vendor/phpoffice/phpspreadsheet/src/PhpSpreadsheet/Style/Conditional.php
@@ -232,7 +232,7 @@ class Conditional implements IComparable
      *
      * @return Conditional
      */
-    public function setStyle(Style $pValue = null)
+    public function setStyle(?Style $pValue = null)
     {
         $this->style = $pValue;
 
diff --git a/lib/vendor/phpoffice/phpspreadsheet/src/PhpSpreadsheet/Worksheet/AutoFilter.php b/lib/vendor/phpoffice/phpspreadsheet/src/PhpSpreadsheet/Worksheet/AutoFilter.php
index 494948a77f..9ffe5bd045 100644
--- a/lib/vendor/phpoffice/phpspreadsheet/src/PhpSpreadsheet/Worksheet/AutoFilter.php
+++ b/lib/vendor/phpoffice/phpspreadsheet/src/PhpSpreadsheet/Worksheet/AutoFilter.php
@@ -38,7 +38,7 @@ class AutoFilter
      * @param string $pRange Cell range (i.e. A1:E10)
      * @param Worksheet $pSheet
      */
-    public function __construct($pRange = '', Worksheet $pSheet = null)
+    public function __construct($pRange = '', ?Worksheet $pSheet = null)
     {
         $this->range = $pRange;
         $this->workSheet = $pSheet;
@@ -61,7 +61,7 @@ class AutoFilter
      *
      * @return AutoFilter
      */
-    public function setParent(Worksheet $pSheet = null)
+    public function setParent(?Worksheet $pSheet = null)
     {
         $this->workSheet = $pSheet;
 
diff --git a/lib/vendor/phpoffice/phpspreadsheet/src/PhpSpreadsheet/Worksheet/AutoFilter/Column.php b/lib/vendor/phpoffice/phpspreadsheet/src/PhpSpreadsheet/Worksheet/AutoFilter/Column.php
index b5ab61e971..1900b01988 100644
--- a/lib/vendor/phpoffice/phpspreadsheet/src/PhpSpreadsheet/Worksheet/AutoFilter/Column.php
+++ b/lib/vendor/phpoffice/phpspreadsheet/src/PhpSpreadsheet/Worksheet/AutoFilter/Column.php
@@ -94,7 +94,7 @@ class Column
      * @param string $pColumn Column (e.g. A)
      * @param AutoFilter $pParent Autofilter for this column
      */
-    public function __construct($pColumn, AutoFilter $pParent = null)
+    public function __construct($pColumn, ?AutoFilter $pParent = null)
     {
         $this->columnIndex = $pColumn;
         $this->parent = $pParent;
@@ -149,7 +149,7 @@ class Column
      *
      * @return Column
      */
-    public function setParent(AutoFilter $pParent = null)
+    public function setParent(?AutoFilter $pParent = null)
     {
         $this->parent = $pParent;
 
diff --git a/lib/vendor/phpoffice/phpspreadsheet/src/PhpSpreadsheet/Worksheet/AutoFilter/Column/Rule.php b/lib/vendor/phpoffice/phpspreadsheet/src/PhpSpreadsheet/Worksheet/AutoFilter/Column/Rule.php
index 450bccdb6a..11c9b7b0be 100644
--- a/lib/vendor/phpoffice/phpspreadsheet/src/PhpSpreadsheet/Worksheet/AutoFilter/Column/Rule.php
+++ b/lib/vendor/phpoffice/phpspreadsheet/src/PhpSpreadsheet/Worksheet/AutoFilter/Column/Rule.php
@@ -240,7 +240,7 @@ class Rule
      *
      * @param Column $pParent
      */
-    public function __construct(Column $pParent = null)
+    public function __construct(?Column $pParent = null)
     {
         $this->parent = $pParent;
     }
@@ -426,7 +426,7 @@ class Rule
      *
      * @return Rule
      */
-    public function setParent(Column $pParent = null)
+    public function setParent(?Column $pParent = null)
     {
         $this->parent = $pParent;
 
diff --git a/lib/vendor/phpoffice/phpspreadsheet/src/PhpSpreadsheet/Worksheet/BaseDrawing.php b/lib/vendor/phpoffice/phpspreadsheet/src/PhpSpreadsheet/Worksheet/BaseDrawing.php
index 98b689729e..1d82cb98b5 100644
--- a/lib/vendor/phpoffice/phpspreadsheet/src/PhpSpreadsheet/Worksheet/BaseDrawing.php
+++ b/lib/vendor/phpoffice/phpspreadsheet/src/PhpSpreadsheet/Worksheet/BaseDrawing.php
@@ -207,7 +207,7 @@ class BaseDrawing implements IComparable
      *
      * @return BaseDrawing
      */
-    public function setWorksheet(Worksheet $pValue = null, $pOverrideOld = false)
+    public function setWorksheet(?Worksheet $pValue = null, $pOverrideOld = false)
     {
         if ($this->worksheet === null) {
             // Add drawing to \PhpOffice\PhpSpreadsheet\Worksheet\Worksheet
@@ -473,7 +473,7 @@ class BaseDrawing implements IComparable
      *
      * @return BaseDrawing
      */
-    public function setShadow(Drawing\Shadow $pValue = null)
+    public function setShadow(?Drawing\Shadow $pValue = null)
     {
         $this->shadow = $pValue;
 
@@ -522,7 +522,7 @@ class BaseDrawing implements IComparable
     /**
      * @param null|Hyperlink $pHyperlink
      */
-    public function setHyperlink(Hyperlink $pHyperlink = null)
+    public function setHyperlink(?Hyperlink $pHyperlink = null)
     {
         $this->hyperlink = $pHyperlink;
     }
diff --git a/lib/vendor/phpoffice/phpspreadsheet/src/PhpSpreadsheet/Worksheet/Column.php b/lib/vendor/phpoffice/phpspreadsheet/src/PhpSpreadsheet/Worksheet/Column.php
index 4baaae1f54..9390915ad0 100644
--- a/lib/vendor/phpoffice/phpspreadsheet/src/PhpSpreadsheet/Worksheet/Column.php
+++ b/lib/vendor/phpoffice/phpspreadsheet/src/PhpSpreadsheet/Worksheet/Column.php
@@ -24,7 +24,7 @@ class Column
      * @param Worksheet $parent
      * @param string $columnIndex
      */
-    public function __construct(Worksheet $parent = null, $columnIndex = 'A')
+    public function __construct(?Worksheet $parent = null, $columnIndex = 'A')
     {
         // Set parent and column index
         $this->parent = $parent;
diff --git a/lib/vendor/phpoffice/phpspreadsheet/src/PhpSpreadsheet/Worksheet/ColumnCellIterator.php b/lib/vendor/phpoffice/phpspreadsheet/src/PhpSpreadsheet/Worksheet/ColumnCellIterator.php
index 389036948e..a0ed0d5491 100644
--- a/lib/vendor/phpoffice/phpspreadsheet/src/PhpSpreadsheet/Worksheet/ColumnCellIterator.php
+++ b/lib/vendor/phpoffice/phpspreadsheet/src/PhpSpreadsheet/Worksheet/ColumnCellIterator.php
@@ -43,7 +43,7 @@ class ColumnCellIterator extends CellIterator
      * @param int $startRow The row number at which to start iterating
      * @param int $endRow Optionally, the row number at which to stop iterating
      */
-    public function __construct(Worksheet $subject = null, $columnIndex = 'A', $startRow = 1, $endRow = null)
+    public function __construct(?Worksheet $subject = null, $columnIndex = 'A', $startRow = 1, $endRow = null)
     {
         // Set subject
         $this->worksheet = $subject;
diff --git a/lib/vendor/phpoffice/phpspreadsheet/src/PhpSpreadsheet/Worksheet/Drawing/Shadow.php b/lib/vendor/phpoffice/phpspreadsheet/src/PhpSpreadsheet/Worksheet/Drawing/Shadow.php
index a1e05d6000..1aac9aa103 100644
--- a/lib/vendor/phpoffice/phpspreadsheet/src/PhpSpreadsheet/Worksheet/Drawing/Shadow.php
+++ b/lib/vendor/phpoffice/phpspreadsheet/src/PhpSpreadsheet/Worksheet/Drawing/Shadow.php
@@ -222,7 +222,7 @@ class Shadow implements IComparable
      *
      * @return Shadow
      */
-    public function setColor(Color $pValue = null)
+    public function setColor(?Color $pValue = null)
     {
         $this->color = $pValue;
 
diff --git a/lib/vendor/phpoffice/phpspreadsheet/src/PhpSpreadsheet/Worksheet/Row.php b/lib/vendor/phpoffice/phpspreadsheet/src/PhpSpreadsheet/Worksheet/Row.php
index 2a379d2cd3..7bb1ab7029 100644
--- a/lib/vendor/phpoffice/phpspreadsheet/src/PhpSpreadsheet/Worksheet/Row.php
+++ b/lib/vendor/phpoffice/phpspreadsheet/src/PhpSpreadsheet/Worksheet/Row.php
@@ -24,7 +24,7 @@ class Row
      * @param Worksheet $worksheet
      * @param int $rowIndex
      */
-    public function __construct(Worksheet $worksheet = null, $rowIndex = 1)
+    public function __construct(?Worksheet $worksheet = null, $rowIndex = 1)
     {
         // Set parent and row index
         $this->worksheet = $worksheet;
diff --git a/lib/vendor/phpoffice/phpspreadsheet/src/PhpSpreadsheet/Worksheet/RowCellIterator.php b/lib/vendor/phpoffice/phpspreadsheet/src/PhpSpreadsheet/Worksheet/RowCellIterator.php
index 4f0140b14e..2632db3dc8 100644
--- a/lib/vendor/phpoffice/phpspreadsheet/src/PhpSpreadsheet/Worksheet/RowCellIterator.php
+++ b/lib/vendor/phpoffice/phpspreadsheet/src/PhpSpreadsheet/Worksheet/RowCellIterator.php
@@ -43,7 +43,7 @@ class RowCellIterator extends CellIterator
      * @param string $startColumn The column address at which to start iterating
      * @param string $endColumn Optionally, the column address at which to stop iterating
      */
-    public function __construct(Worksheet $worksheet = null, $rowIndex = 1, $startColumn = 'A', $endColumn = null)
+    public function __construct(?Worksheet $worksheet = null, $rowIndex = 1, $startColumn = 'A', $endColumn = null)
     {
         // Set subject and row index
         $this->worksheet = $worksheet;
diff --git a/lib/vendor/phpoffice/phpspreadsheet/src/PhpSpreadsheet/Worksheet/Worksheet.php b/lib/vendor/phpoffice/phpspreadsheet/src/PhpSpreadsheet/Worksheet/Worksheet.php
index 1e525a3fec..67cbba7347 100644
--- a/lib/vendor/phpoffice/phpspreadsheet/src/PhpSpreadsheet/Worksheet/Worksheet.php
+++ b/lib/vendor/phpoffice/phpspreadsheet/src/PhpSpreadsheet/Worksheet/Worksheet.php
@@ -344,7 +344,7 @@ class Worksheet implements IComparable
      * @param Spreadsheet $parent
      * @param string $pTitle
      */
-    public function __construct(Spreadsheet $parent = null, $pTitle = 'Worksheet')
+    public function __construct(?Spreadsheet $parent = null, $pTitle = 'Worksheet')
     {
         // Set parent and title
         $this->parent = $parent;
@@ -2770,7 +2770,7 @@ class Worksheet implements IComparable
      *
      * @return Worksheet
      */
-    public function setHyperlink($pCellCoordinate, Hyperlink $pHyperlink = null)
+    public function setHyperlink($pCellCoordinate, ?Hyperlink $pHyperlink = null)
     {
         if ($pHyperlink === null) {
             unset($this->hyperlinkCollection[$pCellCoordinate]);
@@ -2831,7 +2831,7 @@ class Worksheet implements IComparable
      *
      * @return Worksheet
      */
-    public function setDataValidation($pCellCoordinate, DataValidation $pDataValidation = null)
+    public function setDataValidation($pCellCoordinate, ?DataValidation $pDataValidation = null)
     {
         if ($pDataValidation === null) {
             unset($this->dataValidationCollection[$pCellCoordinate]);
diff --git a/lib/vendor/phpoffice/phpspreadsheet/src/PhpSpreadsheet/Writer/Ods/Meta.php b/lib/vendor/phpoffice/phpspreadsheet/src/PhpSpreadsheet/Writer/Ods/Meta.php
index ffe5eff792..c4fa1294b6 100644
--- a/lib/vendor/phpoffice/phpspreadsheet/src/PhpSpreadsheet/Writer/Ods/Meta.php
+++ b/lib/vendor/phpoffice/phpspreadsheet/src/PhpSpreadsheet/Writer/Ods/Meta.php
@@ -16,7 +16,7 @@ class Meta extends WriterPart
      *
      * @return string XML Output
      */
-    public function write(Spreadsheet $spreadsheet = null)
+    public function write(?Spreadsheet $spreadsheet = null)
     {
         if (!$spreadsheet) {
             $spreadsheet = $this->getParentWriter()->getSpreadsheet();
diff --git a/lib/vendor/phpoffice/phpspreadsheet/src/PhpSpreadsheet/Writer/Ods/Mimetype.php b/lib/vendor/phpoffice/phpspreadsheet/src/PhpSpreadsheet/Writer/Ods/Mimetype.php
index d0fed2b379..4aac368525 100644
--- a/lib/vendor/phpoffice/phpspreadsheet/src/PhpSpreadsheet/Writer/Ods/Mimetype.php
+++ b/lib/vendor/phpoffice/phpspreadsheet/src/PhpSpreadsheet/Writer/Ods/Mimetype.php
@@ -13,7 +13,7 @@ class Mimetype extends WriterPart
      *
      * @return string XML Output
      */
-    public function write(Spreadsheet $spreadsheet = null)
+    public function write(?Spreadsheet $spreadsheet = null)
     {
         return 'application/vnd.oasis.opendocument.spreadsheet';
     }
diff --git a/lib/vendor/phpoffice/phpspreadsheet/src/PhpSpreadsheet/Writer/Ods/Settings.php b/lib/vendor/phpoffice/phpspreadsheet/src/PhpSpreadsheet/Writer/Ods/Settings.php
index 18f7ee6d5c..2ad547524f 100644
--- a/lib/vendor/phpoffice/phpspreadsheet/src/PhpSpreadsheet/Writer/Ods/Settings.php
+++ b/lib/vendor/phpoffice/phpspreadsheet/src/PhpSpreadsheet/Writer/Ods/Settings.php
@@ -16,7 +16,7 @@ class Settings extends WriterPart
      *
      * @return string XML Output
      */
-    public function write(Spreadsheet $spreadsheet = null)
+    public function write(?Spreadsheet $spreadsheet = null)
     {
         $objWriter = null;
         if ($this->getParentWriter()->getUseDiskCaching()) {
diff --git a/lib/vendor/phpoffice/phpspreadsheet/src/PhpSpreadsheet/Writer/Ods/Styles.php b/lib/vendor/phpoffice/phpspreadsheet/src/PhpSpreadsheet/Writer/Ods/Styles.php
index eaf5cad952..5deb66576d 100644
--- a/lib/vendor/phpoffice/phpspreadsheet/src/PhpSpreadsheet/Writer/Ods/Styles.php
+++ b/lib/vendor/phpoffice/phpspreadsheet/src/PhpSpreadsheet/Writer/Ods/Styles.php
@@ -16,7 +16,7 @@ class Styles extends WriterPart
      *
      * @return string XML Output
      */
-    public function write(Spreadsheet $spreadsheet = null)
+    public function write(?Spreadsheet $spreadsheet = null)
     {
         $objWriter = null;
         if ($this->getParentWriter()->getUseDiskCaching()) {
diff --git a/lib/vendor/phpoffice/phpspreadsheet/src/PhpSpreadsheet/Writer/Ods/Thumbnails.php b/lib/vendor/phpoffice/phpspreadsheet/src/PhpSpreadsheet/Writer/Ods/Thumbnails.php
index a29a14adbe..dfab0654c6 100644
--- a/lib/vendor/phpoffice/phpspreadsheet/src/PhpSpreadsheet/Writer/Ods/Thumbnails.php
+++ b/lib/vendor/phpoffice/phpspreadsheet/src/PhpSpreadsheet/Writer/Ods/Thumbnails.php
@@ -13,7 +13,7 @@ class Thumbnails extends WriterPart
      *
      * @return string XML Output
      */
-    public function writeThumbnail(Spreadsheet $spreadsheet = null)
+    public function writeThumbnail(?Spreadsheet $spreadsheet = null)
     {
         return '';
     }
diff --git a/lib/vendor/phpoffice/phpspreadsheet/src/PhpSpreadsheet/Writer/Xls/Workbook.php b/lib/vendor/phpoffice/phpspreadsheet/src/PhpSpreadsheet/Writer/Xls/Workbook.php
index 41c8e64e29..ecc4c02e2b 100644
--- a/lib/vendor/phpoffice/phpspreadsheet/src/PhpSpreadsheet/Writer/Xls/Workbook.php
+++ b/lib/vendor/phpoffice/phpspreadsheet/src/PhpSpreadsheet/Writer/Xls/Workbook.php
@@ -1143,7 +1143,7 @@ class Workbook extends BIFFwriter
      *
      * @param \PhpOffice\PhpSpreadsheet\Shared\Escher $pValue
      */
-    public function setEscher(\PhpOffice\PhpSpreadsheet\Shared\Escher $pValue = null)
+    public function setEscher(?\PhpOffice\PhpSpreadsheet\Shared\Escher $pValue = null)
     {
         $this->escher = $pValue;
     }
diff --git a/lib/vendor/phpoffice/phpspreadsheet/src/PhpSpreadsheet/Writer/Xls/Worksheet.php b/lib/vendor/phpoffice/phpspreadsheet/src/PhpSpreadsheet/Writer/Xls/Worksheet.php
index db63fa3442..ce3c44410a 100644
--- a/lib/vendor/phpoffice/phpspreadsheet/src/PhpSpreadsheet/Writer/Xls/Worksheet.php
+++ b/lib/vendor/phpoffice/phpspreadsheet/src/PhpSpreadsheet/Writer/Xls/Worksheet.php
@@ -2566,7 +2566,7 @@ class Worksheet extends BIFFwriter
      *
      * @param \PhpOffice\PhpSpreadsheet\Shared\Escher $pValue
      */
-    public function setEscher(\PhpOffice\PhpSpreadsheet\Shared\Escher $pValue = null)
+    public function setEscher(?\PhpOffice\PhpSpreadsheet\Shared\Escher $pValue = null)
     {
         $this->escher = $pValue;
     }
diff --git a/lib/vendor/phpoffice/phpspreadsheet/src/PhpSpreadsheet/Writer/Xlsx/Chart.php b/lib/vendor/phpoffice/phpspreadsheet/src/PhpSpreadsheet/Writer/Xlsx/Chart.php
index 625fd16de2..2ca0b3780d 100644
--- a/lib/vendor/phpoffice/phpspreadsheet/src/PhpSpreadsheet/Writer/Xlsx/Chart.php
+++ b/lib/vendor/phpoffice/phpspreadsheet/src/PhpSpreadsheet/Writer/Xlsx/Chart.php
@@ -112,7 +112,7 @@ class Chart extends WriterPart
      *
      * @throws WriterException
      */
-    private function writeTitle(XMLWriter $objWriter, Title $title = null)
+    private function writeTitle(XMLWriter $objWriter, ?Title $title = null)
     {
         if ($title === null) {
             return;
@@ -157,7 +157,7 @@ class Chart extends WriterPart
      *
      * @throws WriterException
      */
-    private function writeLegend(XMLWriter $objWriter, Legend $legend = null)
+    private function writeLegend(XMLWriter $objWriter, ?Legend $legend = null)
     {
         if ($legend === null) {
             return;
@@ -215,7 +215,7 @@ class Chart extends WriterPart
      *
      * @throws WriterException
      */
-    private function writePlotArea(XMLWriter $objWriter, \PhpOffice\PhpSpreadsheet\Worksheet\Worksheet $pSheet, PlotArea $plotArea, Title $xAxisLabel = null, Title $yAxisLabel = null, Axis $xAxis = null, Axis $yAxis = null, GridLines $majorGridlines = null, GridLines $minorGridlines = null)
+    private function writePlotArea(XMLWriter $objWriter, \PhpOffice\PhpSpreadsheet\Worksheet\Worksheet $pSheet, PlotArea $plotArea, ?Title $xAxisLabel = null, ?Title $yAxisLabel = null, ?Axis $xAxis = null, ?Axis $yAxis = null, ?GridLines $majorGridlines = null, ?GridLines $minorGridlines = null)
     {
         if ($plotArea === null) {
             return;
@@ -344,7 +344,7 @@ class Chart extends WriterPart
      * @param XMLWriter $objWriter XML Writer
      * @param \PhpOffice\PhpSpreadsheet\Chart\Layout $chartLayout Chart layout
      */
-    private function writeDataLabels(XMLWriter $objWriter, Layout $chartLayout = null)
+    private function writeDataLabels(XMLWriter $objWriter, ?Layout $chartLayout = null)
     {
         $objWriter->startElement('c:dLbls');
 
@@ -1421,7 +1421,7 @@ class Chart extends WriterPart
      * @param XMLWriter $objWriter XML Writer
      * @param Layout $layout
      */
-    private function writeLayout(XMLWriter $objWriter, Layout $layout = null)
+    private function writeLayout(XMLWriter $objWriter, ?Layout $layout = null)
     {
         $objWriter->startElement('c:layout');
 
diff --git a/lib/vendor/phpoffice/phpword/src/PhpWord/Element/AbstractContainer.php b/lib/vendor/phpoffice/phpword/src/PhpWord/Element/AbstractContainer.php
index 6a1ed93013..4dafd0ce72 100644
--- a/lib/vendor/phpoffice/phpword/src/PhpWord/Element/AbstractContainer.php
+++ b/lib/vendor/phpoffice/phpword/src/PhpWord/Element/AbstractContainer.php
@@ -20,32 +20,32 @@ namespace PhpOffice\PhpWord\Element;
 /**
  * Container abstract class
  *
- * @method Text addText(string $text, mixed $fStyle = null, mixed $pStyle = null)
+ * @method Text addText(string $text, ?mixed $fStyle = null, ?mixed $pStyle = null)
  * @method TextRun addTextRun(mixed $pStyle = null)
  * @method Bookmark addBookmark(string $name)
- * @method Link addLink(string $target, string $text = null, mixed $fStyle = null, mixed $pStyle = null, boolean $internal = false)
- * @method PreserveText addPreserveText(string $text, mixed $fStyle = null, mixed $pStyle = null)
- * @method void addTextBreak(int $count = 1, mixed $fStyle = null, mixed $pStyle = null)
- * @method ListItem addListItem(string $txt, int $depth = 0, mixed $font = null, mixed $list = null, mixed $para = null)
- * @method ListItemRun addListItemRun(int $depth = 0, mixed $listStyle = null, mixed $pStyle = null)
+ * @method Link addLink(string $target, ?string $text = null, ?mixed $fStyle = null, ?mixed $pStyle = null, boolean $internal = false)
+ * @method PreserveText addPreserveText(string $text, ?mixed $fStyle = null, ?mixed $pStyle = null)
+ * @method void addTextBreak(int $count = 1, ?mixed $fStyle = null, ?mixed $pStyle = null)
+ * @method ListItem addListItem(string $txt, int $depth = 0, ?mixed $font = null, ?mixed $list = null, ?mixed $para = null)
+ * @method ListItemRun addListItemRun(int $depth = 0, ?mixed $listStyle = null, ?mixed $pStyle = null)
  * @method Footnote addFootnote(mixed $pStyle = null)
  * @method Endnote addEndnote(mixed $pStyle = null)
- * @method CheckBox addCheckBox(string $name, $text, mixed $fStyle = null, mixed $pStyle = null)
+ * @method CheckBox addCheckBox(string $name, $text, ?mixed $fStyle = null, ?mixed $pStyle = null)
  * @method Title addTitle(mixed $text, int $depth = 1)
- * @method TOC addTOC(mixed $fontStyle = null, mixed $tocStyle = null, int $minDepth = 1, int $maxDepth = 9)
+ * @method TOC addTOC(mixed $fontStyle = null, ?mixed $tocStyle = null, int $minDepth = 1, int $maxDepth = 9)
  * @method PageBreak addPageBreak()
  * @method Table addTable(mixed $style = null)
- * @method Image addImage(string $source, mixed $style = null, bool $isWatermark = false, $name = null)
- * @method OLEObject addOLEObject(string $source, mixed $style = null)
+ * @method Image addImage(string $source, ?mixed $style = null, bool $isWatermark = false, $name = null)
+ * @method OLEObject addOLEObject(string $source, ?mixed $style = null)
  * @method TextBox addTextBox(mixed $style = null)
- * @method Field addField(string $type = null, array $properties = array(), array $options = array(), mixed $text = null)
+ * @method Field addField(string $type = null, array $properties = array(), array $options = array(), ?mixed $text = null)
  * @method Line addLine(mixed $lineStyle = null)
- * @method Shape addShape(string $type, mixed $style = null)
- * @method Chart addChart(string $type, array $categories, array $values, array $style = null, $seriesName = null)
- * @method FormField addFormField(string $type, mixed $fStyle = null, mixed $pStyle = null)
+ * @method Shape addShape(string $type, ?mixed $style = null)
+ * @method Chart addChart(string $type, array $categories, array $values, ?array $style = null, $seriesName = null)
+ * @method FormField addFormField(string $type, ?mixed $fStyle = null, ?mixed $pStyle = null)
  * @method SDT addSDT(string $type)
  *
- * @method \PhpOffice\PhpWord\Element\OLEObject addObject(string $source, mixed $style = null) deprecated, use addOLEObject instead
+ * @method \PhpOffice\PhpWord\Element\OLEObject addObject(string $source, ?mixed $style = null) deprecated, use addOLEObject instead
  *
  * @since 0.10.0
  */
diff --git a/lib/vendor/phpoffice/phpword/src/PhpWord/Element/AbstractElement.php b/lib/vendor/phpoffice/phpword/src/PhpWord/Element/AbstractElement.php
index 46372b71db..30cc3fc537 100644
--- a/lib/vendor/phpoffice/phpword/src/PhpWord/Element/AbstractElement.php
+++ b/lib/vendor/phpoffice/phpword/src/PhpWord/Element/AbstractElement.php
@@ -157,7 +157,7 @@ abstract class AbstractElement
      *
      * @param \PhpOffice\PhpWord\PhpWord $phpWord
      */
-    public function setPhpWord(PhpWord $phpWord = null)
+    public function setPhpWord(?PhpWord $phpWord = null)
     {
         $this->phpWord = $phpWord;
     }
diff --git a/lib/vendor/phpoffice/phpword/src/PhpWord/Element/Section.php b/lib/vendor/phpoffice/phpword/src/PhpWord/Element/Section.php
index caf2ca2738..c6ee26935f 100644
--- a/lib/vendor/phpoffice/phpword/src/PhpWord/Element/Section.php
+++ b/lib/vendor/phpoffice/phpword/src/PhpWord/Element/Section.php
@@ -170,7 +170,7 @@ class Section extends AbstractContainer
      *
      * @param FootnoteProperties $footnoteProperties
      */
-    public function setFootnoteProperties(FootnoteProperties $footnoteProperties = null)
+    public function setFootnoteProperties(?FootnoteProperties $footnoteProperties = null)
     {
         $this->footnoteProperties = $footnoteProperties;
     }
diff --git a/lib/vendor/phpoffice/phpword/src/PhpWord/Exception/CopyFileException.php b/lib/vendor/phpoffice/phpword/src/PhpWord/Exception/CopyFileException.php
index d1c3bd0123..eedf6f9883 100644
--- a/lib/vendor/phpoffice/phpword/src/PhpWord/Exception/CopyFileException.php
+++ b/lib/vendor/phpoffice/phpword/src/PhpWord/Exception/CopyFileException.php
@@ -28,7 +28,7 @@ final class CopyFileException extends Exception
      * @param int $code The user defined exception code
      * @param \Exception $previous The previous exception used for the exception chaining
      */
-    final public function __construct($source, $destination, $code = 0, \Exception $previous = null)
+    final public function __construct($source, $destination, $code = 0, ?\Exception $previous = null)
     {
         parent::__construct(
             sprintf('Could not copy \'%s\' file to \'%s\'.', $source, $destination),
diff --git a/lib/vendor/phpoffice/phpword/src/PhpWord/Exception/CreateTemporaryFileException.php b/lib/vendor/phpoffice/phpword/src/PhpWord/Exception/CreateTemporaryFileException.php
index c8a06429d8..a9f3618b56 100644
--- a/lib/vendor/phpoffice/phpword/src/PhpWord/Exception/CreateTemporaryFileException.php
+++ b/lib/vendor/phpoffice/phpword/src/PhpWord/Exception/CreateTemporaryFileException.php
@@ -26,7 +26,7 @@ final class CreateTemporaryFileException extends Exception
      * @param int $code The user defined exception code
      * @param \Exception $previous The previous exception used for the exception chaining
      */
-    final public function __construct($code = 0, \Exception $previous = null)
+    final public function __construct($code = 0, ?\Exception $previous = null)
     {
         parent::__construct(
             'Could not create a temporary file with unique name in the specified directory.',
diff --git a/lib/vendor/phpoffice/phpword/src/PhpWord/Media.php b/lib/vendor/phpoffice/phpword/src/PhpWord/Media.php
index cc1b290312..4154b8e67e 100644
--- a/lib/vendor/phpoffice/phpword/src/PhpWord/Media.php
+++ b/lib/vendor/phpoffice/phpword/src/PhpWord/Media.php
@@ -47,7 +47,7 @@ class Media
      *
      * @return int
      */
-    public static function addElement($container, $mediaType, $source, Image $image = null)
+    public static function addElement($container, $mediaType, $source, ?Image $image = null)
     {
         // Assign unique media Id and initiate media container if none exists
         $mediaId = md5($container . $source);
@@ -214,7 +214,7 @@ class Media
      *
      * @codeCoverageIgnore
      */
-    public static function addSectionMediaElement($src, $type, Image $image = null)
+    public static function addSectionMediaElement($src, $type, ?Image $image = null)
     {
         return self::addElement('section', $type, $src, $image);
     }
@@ -280,7 +280,7 @@ class Media
      *
      * @codeCoverageIgnore
      */
-    public static function addHeaderMediaElement($headerCount, $src, Image $image = null)
+    public static function addHeaderMediaElement($headerCount, $src, ?Image $image = null)
     {
         return self::addElement("header{$headerCount}", 'image', $src, $image);
     }
@@ -328,7 +328,7 @@ class Media
      *
      * @codeCoverageIgnore
      */
-    public static function addFooterMediaElement($footerCount, $src, Image $image = null)
+    public static function addFooterMediaElement($footerCount, $src, ?Image $image = null)
     {
         return self::addElement("footer{$footerCount}", 'image', $src, $image);
     }
diff --git a/lib/vendor/phpoffice/phpword/src/PhpWord/Metadata/Settings.php b/lib/vendor/phpoffice/phpword/src/PhpWord/Metadata/Settings.php
index b1552e0210..f3f2a880d5 100644
--- a/lib/vendor/phpoffice/phpword/src/PhpWord/Metadata/Settings.php
+++ b/lib/vendor/phpoffice/phpword/src/PhpWord/Metadata/Settings.php
@@ -267,7 +267,7 @@ class Settings
      *
      * @param TrackChangesView $trackChangesView
      */
-    public function setRevisionView(TrackChangesView $trackChangesView = null)
+    public function setRevisionView(?TrackChangesView $trackChangesView = null)
     {
         $this->revisionView = $trackChangesView;
     }
diff --git a/lib/vendor/phpoffice/phpword/src/PhpWord/PhpWord.php b/lib/vendor/phpoffice/phpword/src/PhpWord/PhpWord.php
index a78df2c4e5..0e604793e6 100644
--- a/lib/vendor/phpoffice/phpword/src/PhpWord/PhpWord.php
+++ b/lib/vendor/phpoffice/phpword/src/PhpWord/PhpWord.php
@@ -36,10 +36,10 @@ use PhpOffice\PhpWord\Exception\Exception;
  * @method int addComment(Element\Comment $comment)
  *
  * @method Style\Paragraph addParagraphStyle(string $styleName, mixed $styles)
- * @method Style\Font addFontStyle(string $styleName, mixed $fontStyle, mixed $paragraphStyle = null)
+ * @method Style\Font addFontStyle(string $styleName, mixed $fontStyle, ?mixed $paragraphStyle = null)
  * @method Style\Font addLinkStyle(string $styleName, mixed $styles)
- * @method Style\Font addTitleStyle(mixed $depth, mixed $fontStyle, mixed $paragraphStyle = null)
- * @method Style\Table addTableStyle(string $styleName, mixed $styleTable, mixed $styleFirstRow = null)
+ * @method Style\Font addTitleStyle(mixed $depth, mixed $fontStyle, ?mixed $paragraphStyle = null)
+ * @method Style\Table addTableStyle(string $styleName, mixed $styleTable, ?mixed $styleFirstRow = null)
  * @method Style\Numbering addNumberingStyle(string $styleName, mixed $styles)
  */
 class PhpWord
diff --git a/lib/vendor/phpoffice/phpword/src/PhpWord/Reader/Word2007/AbstractPart.php b/lib/vendor/phpoffice/phpword/src/PhpWord/Reader/Word2007/AbstractPart.php
index 729c0b95b0..7928708a41 100644
--- a/lib/vendor/phpoffice/phpword/src/PhpWord/Reader/Word2007/AbstractPart.php
+++ b/lib/vendor/phpoffice/phpword/src/PhpWord/Reader/Word2007/AbstractPart.php
@@ -182,7 +182,7 @@ abstract class AbstractPart
      * @param array $paragraphStyle
      * @return number|null
      */
-    private function getHeadingDepth(array $paragraphStyle = null)
+    private function getHeadingDepth(?array $paragraphStyle = null)
     {
         if (is_array($paragraphStyle) && isset($paragraphStyle['styleName'])) {
             if ('Title' === $paragraphStyle['styleName']) {
@@ -590,7 +590,7 @@ abstract class AbstractPart
      * @param string|array|null $elements
      * @return string|null
      */
-    private function findPossibleElement(XMLReader $xmlReader, \DOMElement $parentNode = null, $elements = null)
+    private function findPossibleElement(XMLReader $xmlReader, ?\DOMElement $parentNode = null, $elements = null)
     {
         if (is_array($elements)) {
             //if element is an array, we take the first element that exists in the XML
@@ -639,7 +639,7 @@ abstract class AbstractPart
      * @ignoreScrutinizerPatch
      * @return array
      */
-    protected function readStyleDefs(XMLReader $xmlReader, \DOMElement $parentNode = null, $styleDefs = array())
+    protected function readStyleDefs(XMLReader $xmlReader, ?\DOMElement $parentNode = null, $styleDefs = array())
     {
         $styles = array();
 
diff --git a/lib/vendor/phpoffice/phpword/src/PhpWord/Shared/XMLReader.php b/lib/vendor/phpoffice/phpword/src/PhpWord/Shared/XMLReader.php
index 3905c52f19..6aac018b2d 100644
--- a/lib/vendor/phpoffice/phpword/src/PhpWord/Shared/XMLReader.php
+++ b/lib/vendor/phpoffice/phpword/src/PhpWord/Shared/XMLReader.php
@@ -91,7 +91,7 @@ class XMLReader
      * @param \DOMElement $contextNode
      * @return \DOMNodeList
      */
-    public function getElements($path, \DOMElement $contextNode = null)
+    public function getElements($path, ?\DOMElement $contextNode = null)
     {
         if ($this->dom === null) {
             return array();
@@ -134,7 +134,7 @@ class XMLReader
      * @param \DOMElement $contextNode
      * @return \DOMElement|null
      */
-    public function getElement($path, \DOMElement $contextNode = null)
+    public function getElement($path, ?\DOMElement $contextNode = null)
     {
         $elements = $this->getElements($path, $contextNode);
         if ($elements->length > 0) {
@@ -152,7 +152,7 @@ class XMLReader
      * @param string $path
      * @return string|null
      */
-    public function getAttribute($attribute, \DOMElement $contextNode = null, $path = null)
+    public function getAttribute($attribute, ?\DOMElement $contextNode = null, $path = null)
     {
         $return = null;
         if ($path !== null) {
@@ -178,7 +178,7 @@ class XMLReader
      * @param \DOMElement $contextNode
      * @return string|null
      */
-    public function getValue($path, \DOMElement $contextNode = null)
+    public function getValue($path, ?\DOMElement $contextNode = null)
     {
         $elements = $this->getElements($path, $contextNode);
         if ($elements->length > 0) {
@@ -195,7 +195,7 @@ class XMLReader
      * @param \DOMElement $contextNode
      * @return int
      */
-    public function countElements($path, \DOMElement $contextNode = null)
+    public function countElements($path, ?\DOMElement $contextNode = null)
     {
         $elements = $this->getElements($path, $contextNode);
 
@@ -209,7 +209,7 @@ class XMLReader
      * @param \DOMElement $contextNode
      * @return bool
      */
-    public function elementExists($path, \DOMElement $contextNode = null)
+    public function elementExists($path, ?\DOMElement $contextNode = null)
     {
         return $this->getElements($path, $contextNode)->length > 0;
     }
diff --git a/lib/vendor/phpoffice/phpword/src/PhpWord/Shared/XMLWriter.php b/lib/vendor/phpoffice/phpword/src/PhpWord/Shared/XMLWriter.php
index 930ad62ee1..03727b8c10 100644
--- a/lib/vendor/phpoffice/phpword/src/PhpWord/Shared/XMLWriter.php
+++ b/lib/vendor/phpoffice/phpword/src/PhpWord/Shared/XMLWriter.php
@@ -25,12 +25,12 @@ namespace PhpOffice\PhpWord\Shared;
  * @method bool openMemory()
  * @method string outputMemory(bool $flush = null)
  * @method bool setIndent(bool $indent)
- * @method bool startDocument(string $version = 1.0, string $encoding = null, string $standalone = null)
+ * @method bool startDocument(string $version = 1.0, ?string $encoding = null, ?string $standalone = null)
  * @method bool startElement(string $name)
  * @method bool text(string $content)
  * @method bool writeCData(string $content)
  * @method bool writeComment(string $content)
- * @method bool writeElement(string $name, string $content = null)
+ * @method bool writeElement(string $name, ?string $content = null)
  * @method bool writeRaw(string $content)
  */
 class XMLWriter extends \XMLWriter
diff --git a/lib/vendor/phpoffice/phpword/src/PhpWord/Shared/ZipArchive.php b/lib/vendor/phpoffice/phpword/src/PhpWord/Shared/ZipArchive.php
index 6517ca8abf..5e8028e164 100644
--- a/lib/vendor/phpoffice/phpword/src/PhpWord/Shared/ZipArchive.php
+++ b/lib/vendor/phpoffice/phpword/src/PhpWord/Shared/ZipArchive.php
@@ -27,7 +27,7 @@ use PhpOffice\PhpWord\Settings;
  * properties and methods are bypassed and used as the model for the PCLZip
  * emulation. Only needed PHP ZipArchive features are implemented.
  *
- * @method  bool addFile(string $filename, string $localname = null)
+ * @method  bool addFile(string $filename, ?string $localname = null)
  * @method  bool addFromString(string $localname, string $contents)
  * @method  string getNameIndex(int $index)
  * @method  int locateName(string $name)
diff --git a/lib/vendor/phpoffice/phpword/src/PhpWord/Style/Table.php b/lib/vendor/phpoffice/phpword/src/PhpWord/Style/Table.php
index f777ac671f..c5012d44d3 100644
--- a/lib/vendor/phpoffice/phpword/src/PhpWord/Style/Table.php
+++ b/lib/vendor/phpoffice/phpword/src/PhpWord/Style/Table.php
@@ -779,7 +779,7 @@ class Table extends Border
      *
      * @param int[] $value
      */
-    public function setColumnWidths(array $value = null)
+    public function setColumnWidths(?array $value = null)
     {
         $this->columnWidths = $value;
     }
diff --git a/lib/vendor/phpoffice/phpword/src/PhpWord/Writer/AbstractWriter.php b/lib/vendor/phpoffice/phpword/src/PhpWord/Writer/AbstractWriter.php
index 2c1ad29460..2c116c0086 100644
--- a/lib/vendor/phpoffice/phpword/src/PhpWord/Writer/AbstractWriter.php
+++ b/lib/vendor/phpoffice/phpword/src/PhpWord/Writer/AbstractWriter.php
@@ -113,7 +113,7 @@ abstract class AbstractWriter implements WriterInterface
      * @param \PhpOffice\PhpWord\PhpWord
      * @return self
      */
-    public function setPhpWord(PhpWord $phpWord = null)
+    public function setPhpWord(?PhpWord $phpWord = null)
     {
         $this->phpWord = $phpWord;
 
diff --git a/lib/vendor/phpoffice/phpword/src/PhpWord/Writer/HTML.php b/lib/vendor/phpoffice/phpword/src/PhpWord/Writer/HTML.php
index 7f55b9d3e6..79aa397160 100644
--- a/lib/vendor/phpoffice/phpword/src/PhpWord/Writer/HTML.php
+++ b/lib/vendor/phpoffice/phpword/src/PhpWord/Writer/HTML.php
@@ -44,7 +44,7 @@ class HTML extends AbstractWriter implements WriterInterface
     /**
      * Create new instance
      */
-    public function __construct(PhpWord $phpWord = null)
+    public function __construct(?PhpWord $phpWord = null)
     {
         $this->setPhpWord($phpWord);
 
diff --git a/lib/vendor/phpoffice/phpword/src/PhpWord/Writer/HTML/Part/AbstractPart.php b/lib/vendor/phpoffice/phpword/src/PhpWord/Writer/HTML/Part/AbstractPart.php
index 97c763759a..ecda6506dc 100644
--- a/lib/vendor/phpoffice/phpword/src/PhpWord/Writer/HTML/Part/AbstractPart.php
+++ b/lib/vendor/phpoffice/phpword/src/PhpWord/Writer/HTML/Part/AbstractPart.php
@@ -49,7 +49,7 @@ abstract class AbstractPart
     /**
      * @param \PhpOffice\PhpWord\Writer\AbstractWriter $writer
      */
-    public function setParentWriter(AbstractWriter $writer = null)
+    public function setParentWriter(?AbstractWriter $writer = null)
     {
         $this->parentWriter = $writer;
     }
diff --git a/lib/vendor/phpoffice/phpword/src/PhpWord/Writer/ODText.php b/lib/vendor/phpoffice/phpword/src/PhpWord/Writer/ODText.php
index efd0d6a923..611e6108c6 100644
--- a/lib/vendor/phpoffice/phpword/src/PhpWord/Writer/ODText.php
+++ b/lib/vendor/phpoffice/phpword/src/PhpWord/Writer/ODText.php
@@ -32,7 +32,7 @@ class ODText extends AbstractWriter implements WriterInterface
      *
      * @param \PhpOffice\PhpWord\PhpWord $phpWord
      */
-    public function __construct(PhpWord $phpWord = null)
+    public function __construct(?PhpWord $phpWord = null)
     {
         // Assign PhpWord
         $this->setPhpWord($phpWord);
diff --git a/lib/vendor/phpoffice/phpword/src/PhpWord/Writer/ODText/Element/Text.php b/lib/vendor/phpoffice/phpword/src/PhpWord/Writer/ODText/Element/Text.php
index 464d277739..5722f523e6 100644
--- a/lib/vendor/phpoffice/phpword/src/PhpWord/Writer/ODText/Element/Text.php
+++ b/lib/vendor/phpoffice/phpword/src/PhpWord/Writer/ODText/Element/Text.php
@@ -124,7 +124,7 @@ class Text extends AbstractElement
         }
     }
 
-    private function writeChangeInsertion($start = true, TrackChange $trackChange = null)
+    private function writeChangeInsertion($start = true, ?TrackChange $trackChange = null)
     {
         if ($trackChange == null || $trackChange->getChangeType() != TrackChange::INSERTED) {
             return;
diff --git a/lib/vendor/phpoffice/phpword/src/PhpWord/Writer/RTF.php b/lib/vendor/phpoffice/phpword/src/PhpWord/Writer/RTF.php
index 0604e8b56b..dc933e19fd 100644
--- a/lib/vendor/phpoffice/phpword/src/PhpWord/Writer/RTF.php
+++ b/lib/vendor/phpoffice/phpword/src/PhpWord/Writer/RTF.php
@@ -38,7 +38,7 @@ class RTF extends AbstractWriter implements WriterInterface
      *
      * @param \PhpOffice\PhpWord\PhpWord $phpWord
      */
-    public function __construct(PhpWord $phpWord = null)
+    public function __construct(?PhpWord $phpWord = null)
     {
         $this->setPhpWord($phpWord);
 
diff --git a/lib/vendor/phpoffice/phpword/src/PhpWord/Writer/RTF/Part/AbstractPart.php b/lib/vendor/phpoffice/phpword/src/PhpWord/Writer/RTF/Part/AbstractPart.php
index 8171b0d228..365af6bbdf 100644
--- a/lib/vendor/phpoffice/phpword/src/PhpWord/Writer/RTF/Part/AbstractPart.php
+++ b/lib/vendor/phpoffice/phpword/src/PhpWord/Writer/RTF/Part/AbstractPart.php
@@ -49,7 +49,7 @@ abstract class AbstractPart
     /**
      * @param \PhpOffice\PhpWord\Writer\AbstractWriter $writer
      */
-    public function setParentWriter(AbstractWriter $writer = null)
+    public function setParentWriter(?AbstractWriter $writer = null)
     {
         $this->parentWriter = $writer;
     }
diff --git a/lib/vendor/phpoffice/phpword/src/PhpWord/Writer/Word2007.php b/lib/vendor/phpoffice/phpword/src/PhpWord/Writer/Word2007.php
index eee215bef0..d2bf858d79 100644
--- a/lib/vendor/phpoffice/phpword/src/PhpWord/Writer/Word2007.php
+++ b/lib/vendor/phpoffice/phpword/src/PhpWord/Writer/Word2007.php
@@ -46,7 +46,7 @@ class Word2007 extends AbstractWriter implements WriterInterface
      *
      * @param \PhpOffice\PhpWord\PhpWord
      */
-    public function __construct(PhpWord $phpWord = null)
+    public function __construct(?PhpWord $phpWord = null)
     {
         // Assign PhpWord
         $this->setPhpWord($phpWord);
diff --git a/lib/vendor/phpoffice/phpword/src/PhpWord/Writer/Word2007/Part/AbstractPart.php b/lib/vendor/phpoffice/phpword/src/PhpWord/Writer/Word2007/Part/AbstractPart.php
index 4bee5c542a..d2cfeba8f5 100644
--- a/lib/vendor/phpoffice/phpword/src/PhpWord/Writer/Word2007/Part/AbstractPart.php
+++ b/lib/vendor/phpoffice/phpword/src/PhpWord/Writer/Word2007/Part/AbstractPart.php
@@ -51,7 +51,7 @@ abstract class AbstractPart
      *
      * @param \PhpOffice\PhpWord\Writer\AbstractWriter $writer
      */
-    public function setParentWriter(AbstractWriter $writer = null)
+    public function setParentWriter(?AbstractWriter $writer = null)
     {
         $this->parentWriter = $writer;
     }
diff --git a/lib/vendor/phpoffice/phpword/src/PhpWord/Writer/Word2007/Part/Settings.php b/lib/vendor/phpoffice/phpword/src/PhpWord/Writer/Word2007/Part/Settings.php
index 4dd8b8bedf..5517f6a35e 100644
--- a/lib/vendor/phpoffice/phpword/src/PhpWord/Writer/Word2007/Part/Settings.php
+++ b/lib/vendor/phpoffice/phpword/src/PhpWord/Writer/Word2007/Part/Settings.php
@@ -220,7 +220,7 @@ class Settings extends AbstractPart
      *
      * @param ProofState $proofState
      */
-    private function setProofState(ProofState $proofState = null)
+    private function setProofState(?ProofState $proofState = null)
     {
         if ($proofState != null && $proofState->getGrammar() !== null && $proofState->getSpelling() !== null) {
             $this->settings['w:proofState'] = array(
@@ -237,7 +237,7 @@ class Settings extends AbstractPart
      *
      * @param TrackChangesView $trackChangesView
      */
-    private function setRevisionView(TrackChangesView $trackChangesView = null)
+    private function setRevisionView(?TrackChangesView $trackChangesView = null)
     {
         if ($trackChangesView != null) {
             $revisionView = array();
@@ -256,7 +256,7 @@ class Settings extends AbstractPart
      *
      * @param Language $language
      */
-    private function setThemeFontLang(Language $language = null)
+    private function setThemeFontLang(?Language $language = null)
     {
         $latinLanguage = ($language == null || $language->getLatin() === null) ? 'en-US' : $language->getLatin();
         $lang = array();