@Override
  public void execute(Runnable command) {
    if (isHandlerThread()) {
      command.run();
    } else {
      super.execute(command);
    }
  }
An {@link ExecutorService} that is backed by the application's main looper.

<p>If the execute is called from the thread of the application's main looper, it will be executed
synchronously.
fbcore/src/main/java/com/facebook/common/executors/UiThreadImmediateExecutorService.java