code: public void enableEdit(ClickHandler editClickHandler) {
  
          if (m_editHandlerRegistration != null) {
              m_editHandlerRegistration.removeHandler();
          }
          m_editHandlerRegistration = m_editButton.addClickHandler(editClickHandler);
          m_editButton.enable();
      }
docs: Enables the edit button with the given click handler.<p>
  
  @param editClickHandler the edit click handler