code: function _extractUrls(urlsContainer, imagePath) {
  	var re = /url\(['"]?([^"']*?)['"]?\)/gi, // Match anything between url( and ), possibly with single or double quotes.
  	    urls = [],
  	    m = re.exec(urlsContainer);
  
  	while (m) {
  		// Keep the entire URL from CSS rule, so that each image can have its own full URL.
  		// Except in the case imagePath is provided: remove the path part (i.e. keep only the file name).
  		urls.push(imagePath ? _stripPath(m[1]) : m[1]);
  		m = re.exec(urlsContainer);
  	}
  
  	return urls;
  }
docs: Read the CSS url (could be path or inline base64), may be multiple. First: normal icon Second: Retina icon