docs: function (items, options) {
              options = options || {};
              var isArr = isArray(items), Self = this;
              return this._checkTransaction(options, function () {
                  return asyncArray(items)
                      .map(function (o) {
                          if (!isInstanceOf(o, Self)) {
                              o = new Self(o);
                          }
                          return o.save(null, options);
                      })
                      .chain(function (res) {
                          return isArr ? res : res[0];
                      });
              });
          }