-Fixed tests

Src/Newtonsoft.Json.Tests/Documentation/Samples/Linq/WriteToJsonFile.cs

@@ -60,5 +60,17 @@ namespace Newtonsoft.Json.Tests.Documentation.Samples.Linq
             }
             #endregion
         }
+
+        public static class File
+        {
+            public static StreamWriter CreateText(string path)
+            {
+                return new StreamWriter(new MemoryStream());
+            }
+
+            public static void WriteAllText(string s1, string s2)
+            {
+            }
+        }
     }
 }

Src/Newtonsoft.Json.Tests/Documentation/Samples/Serializer/SerializeWithJsonSerializerToFile.cs

@@ -34,7 +34,6 @@ using Assert = Newtonsoft.Json.Tests.XUnitAssert;
 #else
 using NUnit.Framework;
 #endif
-using File = System.IO.File;
 
 namespace Newtonsoft.Json.Tests.Documentation.Samples.Serializer
 {
@@ -70,5 +69,17 @@ namespace Newtonsoft.Json.Tests.Documentation.Samples.Serializer
             }
             #endregion
         }
+
+        public static class File
+        {
+            public static StreamWriter CreateText(string path)
+            {
+                return new StreamWriter(new MemoryStream());
+            }
+
+            public static void WriteAllText(string s1, string s2)
+            {
+            }
+        }
     }
 }