[nobug] return this as adapter for ITextEditorExtension*

bundles/org.eclipse.wst.sse.ui/src/org/eclipse/wst/sse/ui/StructuredTextEditor.java

diff --git a/bundles/org.eclipse.wst.sse.ui/src/org/eclipse/wst/sse/ui/StructuredTextEditor.java b/bundles/org.eclipse.wst.sse.ui/src/org/eclipse/wst/sse/ui/StructuredTextEditor.java
index 4521ddb..7ab1d0c 100644
--- a/bundles/org.eclipse.wst.sse.ui/src/org/eclipse/wst/sse/ui/StructuredTextEditor.java
+++ b/bundles/org.eclipse.wst.sse.ui/src/org/eclipse/wst/sse/ui/StructuredTextEditor.java
@@ -128,6 +128,9 @@
 import org.eclipse.ui.texteditor.ITextEditor;
 import org.eclipse.ui.texteditor.ITextEditorActionConstants;
 import org.eclipse.ui.texteditor.ITextEditorActionDefinitionIds;
+import org.eclipse.ui.texteditor.ITextEditorExtension;
+import org.eclipse.ui.texteditor.ITextEditorExtension2;
+import org.eclipse.ui.texteditor.ITextEditorExtension3;
 import org.eclipse.ui.texteditor.ITextEditorExtension4;
 import org.eclipse.ui.texteditor.IUpdate;
 import org.eclipse.ui.texteditor.IWorkbenchActionDefinitionIds;
@@ -1837,7 +1840,7 @@
 		Object result = null;
 		// text editor
 		IStructuredModel internalModel = getInternalModel();
-		if (ITextEditor.class.equals(required)) {
+		if (ITextEditor.class.equals(required) || ITextEditorExtension4.class.equals(required) || ITextEditorExtension3.class.equals(required) || ITextEditorExtension2.class.equals(required) || ITextEditorExtension.class.equals(required)) {
 			result = this;
 		}
 		else if (IWorkbenchSiteProgressService.class.equals(required)) {