code: function sortChildren(parent, sortingFunction) {
    if (!parent.children) return;
    parent.children = new Map([...parent.children.entries()].sort(sortingFunction));
    for (var i = 0; i < parent.children.length; ++i)
      recalculateSiblings(parent.children[i], i);
    for (var child of parent.children.values())
      sortChildren(child, sortingFunction);
  }
docs: sortChildren has major changes, as it now works on Maps rather than Arrays
  from SortableDataGrid._sortChildren()
  @param  {WebInspector.TimelineProfileTree.Node} parent
  @param  {any} sortingFunction