code: public void initialize(CmsEntity entity, CmsEditorBase editor, CmsRootHandler rootHandler) {
  
          m_undo.clear();
          m_redo.clear();
          m_entity = entity;
          m_editor = editor;
          m_rootHandler = rootHandler;
          m_current = new Change(m_entity.cloneEntity(), null, null, 0, null);
          fireStateChange();
      }
docs: Initializes the handler to be used for the given entity.<p>
  
  @param entity the edited entity
  @param editor the editor instance
  @param rootHandler the root attribute handler