Removing editorstack only if it's not the last remaining

def unregister_editorstack(self, editorstack):
        """Removing editorstack only if it's not the last remaining"""
        self.remove_last_focus_editorstack(editorstack)
        if len(self.editorstacks) > 1:
            index = self.editorstacks.index(editorstack)
            self.editorstacks.pop(index)
            return True
        else:
            # editorstack was not removed!
            return False