rxcpp::composite_subscription lifetime;
auto worker =
    rxcpp::observe_on_new_thread().create_coordinator(lifetime).get_worker();
std::vector<std::thread> threads;
for (int i = 0; i < 20; ++i) {
  threads.emplace_back([&worker] {
    worker.schedule([&worker](const auto &) {
      for (size_t i = 0; i < 4294967292l / 6; ++i)
        ;
      printf("Work\n");
    });
  });
}
for (auto &t : threads) {
  t.join();
}
lifetime.unsubscribe();