code: function getDefAttrVal(self, name) {
          var attrs = self.getAttrs(), attrConfig = ensureNonEmpty(attrs, name, 1), valFn = attrConfig.valueFn, val;
          if (valFn && (valFn = normalFn(self, valFn))) {
              val = valFn.call(self);
              if (val !== undefined) {
                  attrConfig.value = val;
              }
              delete attrConfig.valueFn;
              attrs[name] = attrConfig;
          }
          return attrConfig.value;
      }
docs: get default attribute value from valueFn/value get default attribute value from valueFn/value