assertNull(tryInternalFastPathGetFailure(future));
    CancellationException e = assertThrows(CancellationException.class, () -> future.get());
    assertNotNull(e.getCause());
  }

  public void testSetFuture_misbehavingFutureDoesNotThrow() throws Exception {
    ListenableFuture<String> badFuture =
        new ListenableFuture<String>() {
          @Override
          public boolean cancel(boolean interrupt) {
            return false;

    assertNull(tryInternalFastPathGetFailure(future));
    CancellationException e = assertThrows(CancellationException.class, () -> future.get());
    assertNotNull(e.getCause());
  }

  public void testSetFuture_misbehavingFutureDoesNotThrow() throws Exception {
    ListenableFuture<String> badFuture =
        new ListenableFuture<String>() {
          @Override
          public boolean cancel(boolean interrupt) {
            return false;

    assertThat(expected).hasCauseThat().isInstanceOf(IllegalArgumentException.class);
    assertThat(expected).hasCauseThat().hasMessageThat().contains(badFuture.toString());
  }

  public void testSetFuture_misbehavingFutureDoesNotThrow() throws Exception {
    SettableFuture<String> future = SettableFuture.create();
    ListenableFuture<String> badFuture =
        new ListenableFuture<String>() {
          @Override