code: function revalue(node, depth) {
      var children = node.children,
          v = 0;
      if (children && (n = children.length)) {
        var i = -1,
            n,
            j = depth + 1;
        while (++i < n) v += revalue(children[i], j);
      } else if (value) {
        v = +value.call(hierarchy, d3_layout_hierarchyInline ? node : node.data, depth) || 0;
      }
      if (value) node.value = v;
      return v;
    }
docs: Recursively re-evaluates the node value.