docs: function next() {
  		for (var _len2 = arguments.length, args = Array(_len2), _key2 = 0; _key2 < _len2; _key2++) {
  			args[_key2] = arguments[_key2];
  		}
  
  		// if the next function has been defined
  		if (typeof utils.queue[utils.i + 1] !== 'undefined') {
  			var _utils$queue;
  
  			args.unshift(next);
  			utils.i++;
  			return (_utils$queue = utils.queue)[utils.i].apply(_utils$queue, args);
  		}
  
  		// if there are no more function, next will re-init fang group
  		return init(args);
  	}