code: function(node) {
        me.current_ = node;
        if (!node) {
          return me.defaultOnSuccess_(node);
        }
        var x = /** @type {ydn.db.con.simple.Node} */ (node.value);
        var e_key = x.getKey();
        var cmp = ydn.db.cmp(e_key, key);
        if (me.reverse) {
          if (cmp != 1) {
            return me.defaultOnSuccess_(node);
          }
        } else {
          if (cmp != -1) {
            return me.defaultOnSuccess_(node);
          }
        }
      }
docs: Node traversal function.
  @param {goog.structs.AvlTree.Node} node
  @return {boolean|undefined} continuation.