code: function(doc) {
          var node_list = doc.getElementsByTagName("node");
          var nodes = {};
          for (var i = 0; i < node_list.length; i++) {
              var node = node_list[i];
              var id = node.getAttribute("id");
              nodes[id] = {
                  'lat': node.getAttribute("lat"),
                  'lon': node.getAttribute("lon"),
                  'node': node
              };
          }
          return nodes;
      }
docs: Method: getNodes
  Return the node items from a doc.
  
  Parameters:
  doc - {DOMElement} node to parse tags from