docs: function (p) {
      var _this = this;
      // brute force search
      var hit = null;
      try {
        morpheus.DendrogramUtil.dfs(this.tree.rootNode, function (node) {
          var xy = _this.toPix(node);
          if (Math.abs(xy[0] - p.x) < 4 && Math.abs(xy[1] - p.y) < 4) {
            hit = node;
            throw 'break';
          }
          return hit === null;
        });
      }
      catch (x) {
        // break of out dfs
      }
      return hit;
    }