docs: function () {
                  var res = [];
                  this._removeAllToArray(this._objectKeys, res);
                  this._objectKeys = null;
                  this._removeAllToArray(this._stringKeys, res);
                  this._stringKeys = null;
                  this._removeAllToArray(this._numberKeys, res);
                  this._numberKeys = null;
                  this._removeAllToArray(this._otherKeys, res);
                  this._otherKeys = null;
                  return res;
              }