code: function (key, value) {
              var self = this,
                  _queryMap,
                  currentValue;
              if (typeof key == 'string') {
                  parseQuery(self);
                  _queryMap = self._queryMap;
                  currentValue = _queryMap[key];
                  if (currentValue === undefined) {
                      currentValue = value;
                  } else {
                      currentValue = [].concat(currentValue).concat(value);
                  }
                  _queryMap[key] = currentValue;
              } else {
                  if (key instanceof Query) {
                      key = key.get();
                  }
                  for (var k in key) {
                      self.add(k, key[k]);
                  }
              }
              return self;
          }
docs: Add parameter value corresponding to current key
  @param {String} key
  @param value
  @chainable