Bug 52064 Content assist in "New Class" Dialog shows interfaces
Content Assist is available for the superclass in M7. However it also lists interfaces. If an interface is selected, the generated class "extends" it instead of "implementing" it.
org.eclipse.jdt.ui/ui/org/eclipse/jdt/ui/wizards/NewTypeWizardPage.java
ICompilationUnit cu= (ICompilationUnit) elem.getAncestor(IJavaElement.COMPILATION_UNIT);
				if (cu != null) {
					enclosingType= cu.findPrimaryType();
				}
			}
			
			try {
				IType type= null;
				if (elem.getElementType() == IJavaElement.TYPE) {
					type= (IType)elem;
					if (type.exists()) {
						String superName= JavaModelUtil.getFullyQualifiedName(type);
						if (type.isInterface()) {
							initSuperinterfaces.add(superName);
						} else {
							initSuperclass= superName;
						}
					}
				}
			} catch (JavaModelException e) {
				JavaPlugin.log(e);
				
			}
		}
		
		String typeName= ""; 
		
		ITextSelection selection= getCurrentTextSelection();
		if (selection != null) {
			String text= selection.getText();