docs: function () {
              var args = comb(arguments).toArray(), cb;
              var last = args[args.length - 1];
              if (isFunction(last) && last.length > 0) {
                  cb = args.pop();
              }
              var ret = this;
              if (args.length) {
                  ret = ret.filter.apply(ret, args);
              }
              return ret.singleRecord(cb);
          }