synchronized (monitor) {
        assertFalse(wasCalled);
        wasCalled = true;
        assertThat(result).isEqualTo(value);
      }
    }

    @Override
    public synchronized void onFailure(Throwable t) {
      synchronized (monitor) {
        assertFalse(wasCalled);
        wasCalled = true;
        assertThat(t).isEqualTo(failure);
      }
    }
  }

      synchronized (monitor) {
        assertFalse(wasCalled);
        wasCalled = true;
        assertThat(result).isEqualTo(value);
      }
    }

    @Override
    public synchronized void onFailure(Throwable t) {
      synchronized (monitor) {
        assertFalse(wasCalled);
        wasCalled = true;
        assertThat(t).isEqualTo(failure);
      }
    }
  }

      assertTrue("Listener called before it was expected", expectCall);
      assertFalse("Listener called more than once", wasCalled());
      calledCountDown.countDown();
    }

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

    boolean wasCalled() {
      return calledCountDown.getCount() == 0;
    }

    void waitForCall() throws InterruptedException {

    boolean wasCalled = false; // must be set in load()
    String keyPrefix = KEY_PREFIX;
    int valuePrefix = VALUE_PREFIX;

    WatchedCreatorLoader() {}

    void reset() {
      wasCalled = false;
    }

    boolean wasCalled() {
      return wasCalled;
    }

    void setKeyPrefix(String keyPrefix) {

      assertTrue("Listener called before it was expected", expectCall);
      assertFalse("Listener called more than once", wasCalled());
      calledCountDown.countDown();
    }

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

    boolean wasCalled() {
      return calledCountDown.getCount() == 0;
    }

    void waitForCall() throws InterruptedException {

      assertTrue("Listener called before it was expected", expectCall);
      assertFalse("Listener called more than once", wasCalled());
      called.set(true);
    }

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

    boolean wasCalled() {
      return called.get();
    }
  }

  public void testAllAsList() throws Exception {

      assertTrue("Listener called before it was expected", expectCall);
      assertFalse("Listener called more than once", wasCalled());
      called.set(true);
    }

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

    boolean wasCalled() {
      return called.get();
    }
  }

  public void testAllAsList() throws Exception {

    fail("Should detect problem in " + FailOnOneOfTwoConstructors.class.getSimpleName());
  }

  public static class NullBounds<T extends @Nullable Object, U extends T, X> {
    boolean xWasCalled;

    public void x(X x) {
      xWasCalled = true;
      checkNotNull(x);
    }

    public void t(T t) {
      fail("Method with parameter <T extends @Nullable Object> should not be called");
    }