if (simgrid::instr::Container::getRoot() == nullptr) {
simgrid::instr::NetZoneContainer* root = new simgrid::instr::NetZoneContainer(id, 0, nullptr);
if (simgrid::instr::Container::getRoot() == nullptr) {
simgrid::instr::NetZoneContainer* root = new simgrid::instr::NetZoneContainer(id, 0, nullptr);