docs: function computeNodeValues(nodes) {
      zrUtil.each(nodes, function (node) {
          var value1 = sum(node.outEdges, getEdgeValue);
          var value2 = sum(node.inEdges, getEdgeValue);
          var value = Math.max(value1, value2);
          node.setLayout({value: value}, true);
      });
  }