docs: function (value) {
                  var type = typeof value,
                      checkLength = false;
                  if (value && type != 'string') {
                      // Functions have a length property, so we need to filter them out
                      if (type == 'function') {
                          // In Safari, NodeList/HTMLCollection both return "function" when using typeof, so we need
                          // to explicitly check them here.
  //                        if (Ext.isSafari) {
  //                            checkLength = value instanceof NodeList || value instanceof HTMLCollection;
  //                        }
                      } else {
                          checkLength = true;
                      }
                  }
                  return checkLength ? value.length !== undefined : false;
              }