Fix compilation warnings in code coverage addin.

src/AddIns/Analysis/CodeCoverage/Test/Gui/TreeViewAfterSelectTestFixture.cs

@@ -33,7 +33,7 @@ namespace ICSharpCode.CodeCoverage.Tests.Gui
 		public void NonCodeCoverageNodeNotInitialised()
 		{
 			DerivedCodeCoverageTreeView treeView = new DerivedCodeCoverageTreeView();
-			DerivedExtTreeNode node = new DerivedExtTreeNode();
+			ExtTreeNode node = new ExtTreeNode();
 			treeView.CallOnAfterSelect(node);
 			Assert.IsFalse(node.IsInitialized);
 		}

src/AddIns/Analysis/CodeCoverage/Test/Utils/DerivedCodeCoverageTreeView.cs

@@ -20,19 +20,6 @@ namespace ICSharpCode.CodeCoverage.Tests.Utils
 		}
 	}
 	
-	/// <summary>
-	/// Derived ExtTreeNode class so we can check the IsInitialized
-	/// property.
-	/// </summary>
-	public class DerivedExtTreeNode : ExtTreeNode
-	{
-		public bool IsInitialized {
-			get {
-				return base.isInitialized;
-			}
-		}
-	}
-	
 	/// <summary>
 	/// Derived CodeCoverageTreeNode class so we can check the IsInitialized
 	/// property.
@@ -43,11 +30,5 @@ namespace ICSharpCode.CodeCoverage.Tests.Utils
 			: base(name, index)
 		{
 		}
-		
-		public bool IsInitialized {
-			get {
-				return base.isInitialized;
-			}
-		}
 	}
 }