docs: function (arr, defaultOp) {
              var ret = [];
              arr.forEach(function (a) {
                  if (isString(a)) {
                      a = this.stringToIdentifier(a);
                  }
                  if (isInstanceOf(a, Identifier)) {
                      ret.push([a, defaultOp]);
                  } else if (isHash(a)) {
                      ret = ret.concat(array.toArray(a));
                  } else {
                      throw new QueryError("Invalid condition specifier " + a);
                  }
              }, this);
              return ret;
          }