code: public void ensureChangeHandlers() {
  
          if (!m_changeHandlerRegistry.isEmpty()) {
              for (HandlerRegistration reg : m_changeHandlerRegistry.values()) {
                  reg.removeHandler();
              }
              m_changeHandlerRegistry.clear();
          }
          for (List<CmsEntity> attr : m_entityAttributes.values()) {
              for (CmsEntity child : attr) {
                  registerChangeHandler(child);
                  child.ensureChangeHandlers();
              }
          }
      }
docs: Ensures that the change event is also fired on child entity change.<p>