code: public void prepareForEdit(
          final String clientId,
          final String editOption,
          final I_CmsSimpleCallback<CmsUUID> callback) {
  
          CmsRpcAction<CmsUUID> action = new CmsRpcAction<CmsUUID>() {
  
              @Override
              public void execute() {
  
                  getContainerpageService().prepareForEdit(
                      clientId,
                      editOption,
                      getData().getRpcContext().getPageStructureId(),
                      getData().getRequestParams(),
                      this);
              }
  
              @Override
              protected void onResponse(CmsUUID result) {
  
                  callback.execute(result);
              }
          };
          action.execute();
      }
docs: Calls the edit handler to prepare the given content element for editing.<p>
  
  @param clientId the element id
  @param editOption the selected edit option
  @param callback the callback to execute