TestExecutor testExecutor = new TestExecutor(mock);

    @SuppressWarnings("unused") // https://errorprone.info/bugpattern/FutureReturnValueIgnored
    Future<?> possiblyIgnoredError = testExecutor.schedule(DO_NOTHING, 10, TimeUnit.MINUTES);
    mock.assertLastMethodCalled("scheduleRunnable", 10, TimeUnit.MINUTES);

    @SuppressWarnings("unused") // https://errorprone.info/bugpattern/FutureReturnValueIgnored

   * mentioned in the method Javadoc does in fact compile.
   */

  @SuppressWarnings("unused") // compilation test
  public void testSampleCodeError1() {
    Optional<Integer> optionalInt = getSomeOptionalInt();
    // Number value = optionalInt.or(0.5); // error
  }

  @SuppressWarnings("unused") // compilation test
  public void testSampleCodeError2() {

  public static class PublicFoo {}

  static class FooTest {
    @SuppressWarnings("unused") // accessed reflectively
    public void testPublic() {}

    @SuppressWarnings("unused") // accessed reflectively
    void testNotPublic() {}
  }

  // Shouldn't be mistaken as Foo's test
  static class Foo2Test {
    @SuppressWarnings("unused") // accessed reflectively
    public void testPublic() {}
  }

  public static class PublicFoo {}

  static class FooTest {
    @SuppressWarnings("unused") // accessed reflectively
    public void testPublic() {}

    @SuppressWarnings("unused") // accessed reflectively
    void testNotPublic() {}
  }

  // Shouldn't be mistaken as Foo's test
  static class Foo2Test {
    @SuppressWarnings("unused") // accessed reflectively
    public void testPublic() {}
  }

  @CollectionSize.Require(absent = ZERO)
  public void testCreateWithNull_unsupported() {
    E[] array = createArrayWithNullElement();

    try {
      // TODO(kak): remove unused capture
      Object unused = getSubjectGenerator().create(array);
      fail("Creating a collection containing null should fail");
    } catch (NullPointerException expected) {
    }
  }

  /**

   */

  public void testSize() {
    int unused = create().size();
  }

  public void testIsEmpty() {
    boolean unused = create().isEmpty();
  }

  public void testRemove() {
    create().remove(null);
  }

  public void testClear() {
    create().clear();
  }

  public void testContainsKey() {
    boolean unused = create().containsKey(null);
  }

    sink.putByte((byte) 7);
    sink.putBytes(new byte[] {});
    sink.putBytes(new byte[] {8});
    HashCode unused = sink.hash();
    sink.assertInvariants(8);
    sink.assertBytes(expected);
  }

  public void testShort() {
    Sink sink = new Sink(4);
    sink.putShort((short) 0x0201);
    HashCode unused = sink.hash();
    sink.assertInvariants(2);
    sink.assertBytes(new byte[] {1, 2, 0, 0}); // padded with zeros
  }

    assertThrows(
        IllegalStateException.class,
        () -> {
          FluentFuture<Closeable> unused = closingFuture.finishToFuture();
        });
  }

  public void testFinishToFuture_preventsFurtherDerivation() {
    ClosingFuture<String> closingFuture = ClosingFuture.from(immediateFuture("value1"));
    FluentFuture<String> unused = closingFuture.finishToFuture();
    assertDerivingThrowsIllegalStateException(closingFuture);
  }

  }

  private void assertGood(String spec) throws ParseException {
    // Throws exception if not working correctly
    HostSpecifier unused = HostSpecifier.fromValid(spec);
    unused = HostSpecifier.from(spec);
    assertTrue(HostSpecifier.isValid(spec));
  }

  private void assertBad(String spec) {
    try {
      HostSpecifier.fromValid(spec);

                return closer.eventuallyClose(mockCloseable, executor);
              }
            },
            executor);
    FluentFuture<Closeable> unused = closingFuture.finishToFuture();
    assertThrows(
        IllegalStateException.class,
        () ->
            closingFuture.finishToValueAndCloser(