docs: function range(start, length) {
        var rgArr = [];
        if (isNum(start)) {
          function rangeLoop(isAdd) {
            if (length >= 0) {
              for (var i = 0; i < length; i++) rgArr.push(isAdd ? i + start : i);
            } else if (length < 0) {
              for (var i = 0; i > length; i--) rgArr.push(isAdd ? i + start : i);
            }
          };
          if (isUdf(length)) {
            length = start, start = UDF;
            rangeLoop(false);
          } else if (isNum(length)) {
            rangeLoop(true);
          }
        }
        return rgArr;
      }