function createRange(fromRight) {
      return function(start, end, step) {
        if (step && typeof step != 'number' && isIterateeCall(start, end, step)) {
          end = step = undefined;
        }
        // Ensure the sign of `-0` is preserved.
        start = toFinite(start);
        if (end === undefined) {
          end = start;
          start = 0;
        } else {
          end = toFinite(end);
        }
        step = step === undefined ? (start < end ? 1 : -1) : toFinite(step);
        return baseRange(start, end, step, fromRight);
      };
    }
Creates a `_.range` or `_.rangeRight` function.

@private
@param {boolean} [fromRight] Specify iterating from right to left.
@returns {Function} Returns the new range function.