code: public boolean setEditMode(CmsMessageBundleEditorTypes.EditMode mode) {
  
          try {
              if ((mode == CmsMessageBundleEditorTypes.EditMode.MASTER) && (null == m_descFile)) {
                  m_descFile = LockedFile.lockResource(m_cms, m_desc);
              }
              m_editMode = mode;
          } catch (CmsException e) {
              return false;
          }
          return true;
      }
docs: Set the edit mode.
  @param mode the edit mode to set.
  @return flag, indicating if the mode could be changed.