code: function  (node, attributeName) {
  			if(!node){
  				return null;
  			}
  			if(this.hasAttribute(node, attributeName)){
  				return this.getAttribute(node, attributeName);
  			}else{
  				var parent = node.parentNode;
  				if(parent){
  					return this.getFirstAncestorAttribute(parent, attributeName);
  				}else{
  					return null;
  				}
  			}
  		}
docs: get a node's path
  
  @param  {DOM Node} node
  @param  {String} attributeName
  @return {String || null}