code: function(doc, nodes, selector, xml) {
          var target = module.exports.resolveParent(doc, selector);
          if (!target) return false;
  
          // saves the attributes of the original xml before making changes
          xml.oldAttrib = _.extend({}, target.attrib);
  
          nodes.forEach(function (node) {
              var attributes = node.attrib;
              for (var attribute in attributes) {
                  target.attrib[attribute] = node.attrib[attribute];
              }
          });
  
          return true;
      }
docs: adds new attributes to doc at selector Will only merge if attribute has not been modified already or --force is used