code: function setWrapToString(wrapper, reference, bitmask) {
        var source = (reference + '');
        return setToString(wrapper, insertWrapDetails(source, updateWrapDetails(getWrapDetails(source), bitmask)));
      }
docs: Sets the `toString` method of `wrapper` to mimic the source of `reference`
  with wrapper details in a comment at the top of the source body.
  
  @private
  @param {Function} wrapper The function to modify.
  @param {Function} reference The reference function.
  @param {number} bitmask The bitmask flags. See `createWrap` for more details.
  @returns {Function} Returns `wrapper`.