code: function(node, tagNames, attributeName) {
  			var i = tagNames.length;
  
  			while(i--) {
  				if(node.tagName.toLowerCase() === tagNames[i]) {
  					var attrValue = this.getAttribute(node, attributeName);
  					if(attrValue && attrValue !== '') {
  						return attrValue;
  					}
  				}
  			}
  			return null;
  		}
docs: gets attribute value from controlled list of tags
  
  @param  {Array} tagNames
  @param  {String} attributeName
  @return {String || null}