code: function nodeBeforeLocation(location) {
          var node;
          exports.root.each(function each(n) {
              if (!n.location || location < n.location) {
                  return true;
              }
              if (!node || node.location < n.location) {
                  node = n;
              }
          });
          return node;
      }
docs: {integer} number of pending requests before initial loading is complete Get the last node before the given location
  @param {integer} location