code: protected static CatalystThread getThread(ExecutorService executor) {
      final AtomicReference<CatalystThread> thread = new AtomicReference<>();
      try {
        executor.submit(() -> {
          thread.set((CatalystThread) Thread.currentThread());
        }).get();
      } catch (InterruptedException | ExecutionException e) {
        throw new IllegalStateException("failed to initialize thread state", e);
      }
      return thread.get();
    }
docs: Gets the thread from a single threaded executor service.