code: function _flags() {
  	  var that = _anObject(this);
  	  var result = '';
  	  if (that.global) result += 'g';
  	  if (that.ignoreCase) result += 'i';
  	  if (that.multiline) result += 'm';
  	  if (that.unicode) result += 'u';
  	  if (that.sticky) result += 'y';
  	  return result;
  	}
docs: 21.2.5.3 get RegExp.prototype.flags