}

  public void testNullTimeUnit() throws Exception {
    future.set(1);
    assertThrows(NullPointerException.class, () -> future.get(0, null));
  }

  public void testNegativeTimeout() throws Exception {
    future.set(1);
    assertEquals(1, future.get(-1, SECONDS).intValue());
  }

  @J2ktIncompatible
  @GwtIncompatible // threads