code: public void loadDefinition(
          final String entityId,
          final CmsEntity editedEntity,
          final I_CmsSimpleCallback<CmsContentDefinition> callback) {
  
          CmsRpcAction<CmsContentDefinition> action = new CmsRpcAction<CmsContentDefinition>() {
  
              @Override
              public void execute() {
  
                  start(0, true);
                  getService().loadDefinition(
                      entityId,
                      m_clientId,
                      editedEntity,
                      getSkipPaths(),
                      m_context.getSettingPresets(),
                      this);
              }
  
              @Override
              protected void onResponse(final CmsContentDefinition result) {
  
                  registerContentDefinition(result);
                  WidgetRegistry.getInstance().registerExternalWidgets(
                      result.getExternalWidgetConfigurations(),
                      new Command() {
  
                          public void execute() {
  
                              stop(false);
                              callback.execute(result);
                          }
                      });
              }
          };
          action.execute();
      }
docs: Loads the content definition for the given entity and executes the callback on success.<p>
  
  @param entityId the entity id
  @param editedEntity the currently edited entity
  @param callback the callback