code: function syncClientId() {
                          var relatedElement = instance.relatedElement || instance.$relatedElement
                          if (relatedElement) {
                              // element
                              if (relatedElement.nodeType && (relatedElement.clientId === undefined)) {
                                  relatedElement.clientId = options.clientId
                              } else if (relatedElement.length) {
                                  // [ element ]
                                  Util.each(relatedElement, function(item /*, index*/ ) {
                                      if (item.nodeType && (item.clientId === undefined)) {
                                          item.clientId = options.clientId
                                          item.setAttribute('data-moduleId', options.moduleId)
                                          item.setAttribute('data-clientId', options.clientId)
                                      }
                                  })
                              }
                          }
                      }
docs: 同步 clientId