fRefactoringProxies= null;
	public void inputChanged(final Viewer viewer, final Object predecessor, final Object successor) {		if (predecessor == successor)			return;		if (successor instanceof RefactoringHistory)			fRefactoringHistory= (RefactoringHistory) successor;		else			fRefactoringHistory= null;		fRefactoringRoots= null;		fRefactoringStamps= null;	}