code: function makeSpritePath(options, groups) {
  	var base = options.spritePath;
  	var file;
  
  	// If is svg, do st
  	if (groups.indexOf('GROUP_SVG_FLAG') > -1) {
  		groups = _.filter(groups, function (item) {
  			return item !== 'GROUP_SVG_FLAG';
  		});
  		file = path.resolve(base, groups.join('.') + '.svg');
  	} else {
  		file = path.resolve(base, groups.join('.') + '.png');
  	}
  
  	return file.replace('.@', options.retinaInfix);
  }
docs: Set the sprite file name form groups.