code: function(key, silent){
              this._configs = this._configs || {};
              if (this._configs[key]) {
                  this.set(key, this._configs[key]._initialConfig.value, silent);
                  return true;
              }
              return false;
          }
docs: Resets the specified attribute's value to its initial value.
  @method resetValue
  @param {String} key The name of the attribute
  @param {Boolean} silent Whether or not to suppress change events
  @return {Boolean} Whether or not the value was set