private final AtomicBoolean called = new AtomicBoolean();

    @Override
    public void run() {
      assertTrue("Listener called before it was expected", expectCall);
      assertFalse("Listener called more than once", wasCalled());
      called.set(true);
    }

    public void expectCall() {
      assertFalse("expectCall is already true", expectCall);
      expectCall = true;
    }

    private final AtomicBoolean called = new AtomicBoolean();

    @Override
    public void run() {
      assertTrue("Listener called before it was expected", expectCall);
      assertFalse("Listener called more than once", wasCalled());
      called.set(true);
    }

    public void expectCall() {
      assertFalse("expectCall is already true", expectCall);
      expectCall = true;
    }