// Sort by the centre line of the extents
stable_sort(items.begin(), items.end(),
[](const shared_ptr<TraceTreeItem> &a, const shared_ptr<TraceTreeItem> &b) {
const auto aext = a->v_extents();
const auto bext = b->v_extents();
// Sort by the centre line of the extents
stable_sort(items.begin(), items.end(),
[](const shared_ptr<TraceTreeItem> &a, const shared_ptr<TraceTreeItem> &b) {
const auto aext = a->v_extents();
const auto bext = b->v_extents();