-add tests for base class object events

Src/Newtonsoft.Json.Tests/TestObjects/SerializationEventTestObject.cs

@@ -96,4 +96,40 @@ namespace Newtonsoft.Json.Tests.TestObjects
       errorContext.Handled = true;
     }
   }
-}
+
+  public class DerivedSerializationEventTestObject : SerializationEventTestObject
+  {
+    // This field is set to null, but populated after deserialization, only
+    // in the derived class
+    [JsonIgnore]
+    public string Member7 { get; set; }
+
+    // These empty methods exist to make sure we're not covering up the base
+    // methods
+    [OnSerializing]
+    internal void OnDerivedSerializingMethod(StreamingContext context)
+    {
+    }
+
+    [OnSerialized]
+    internal void OnDerivedSerializedMethod(StreamingContext context)
+    {
+    }
+
+    [OnDeserializing]
+    internal void OnDerivedDeserializingMethod(StreamingContext context)
+    {
+    }
+
+    [OnDeserialized]
+    internal void OnDerivedDeserializedMethod(StreamingContext context)
+    {
+      Member7 = "This value was set after deserialization.";
+    }
+
+    [OnError]
+    internal void OnDerivedErrorMethod(StreamingContext context, ErrorContext errorContext)
+    {
+    }
+  }
+}