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);
  }

   *
   * How this works is best explained with an example:
   *
   * For a RateLimiter that produces 1 token per second, every second that goes by with the
   * RateLimiter being unused, we increase storedPermits by 1. Say we leave the RateLimiter unused
   * for 10 seconds (i.e., we expected a request at time X, but we are at time X + 10 seconds before
   * a request actually arrives; this is also related to the point made in the last paragraph), thus

    } catch (ClassCastException tolerated) {
    }
    assertTrue(map.containsKey(map.keySet().iterator().next()));
    if (allowsNullKeys) {
      boolean unused = map.containsKey(null);
    } else {
      try {
        boolean unused2 = map.containsKey(null);
      } catch (NullPointerException optional) {
      }
    }
    assertInvariants(map);
  }

  public void testContainsValue() {

    public static void christenPoodle(String unused) {
      throw new UnsupportedOperationException();
    }
  }

  private static class ThrowsSomethingElse {
    @Keep
    public static void christenPoodle(String unused) {
      throw new RuntimeException();
    }
  }

  private interface InterfaceStaticMethodFailsToCheckNull {
    static String create(String unused) {
      return "I don't check";
    }

   */

  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);
  }

    if tags:
        output["tags"] = tags
    if external_docs:
        output["externalDocs"] = external_docs

    CountDownLatch latch = new CountDownLatch(1);
    Object unused =
        new Object() {
          @SuppressWarnings({"removal", "Finalize"}) // b/487687332
          @Override
          protected void finalize() {
            latch.countDown();
          }
        };
    unused = null; // Hint to the JIT that unused is unreachable
    GcFinalization.await(latch);
    assertEquals(0, latch.getCount());
  }

    executor.shutdown();
  }

  public void testCallableStartsAfterFirstFutureCompletes() {
    @SuppressWarnings({"unused", "nullness"})
    Future<?> possiblyIgnoredError = serializer.submitAsync(firstCallable, directExecutor());
    TestCallable secondCallable = new TestCallable(immediateVoidFuture());
    @SuppressWarnings({"unused", "nullness"})
    Future<?> possiblyIgnoredError1 = serializer.submitAsync(secondCallable, directExecutor());

    executor.shutdown();
  }

  public void testCallableStartsAfterFirstFutureCompletes() {
    @SuppressWarnings({"unused", "nullness"})
    Future<?> possiblyIgnoredError = serializer.submitAsync(firstCallable, directExecutor());
    TestCallable secondCallable = new TestCallable(immediateVoidFuture());
    @SuppressWarnings({"unused", "nullness"})
    Future<?> possiblyIgnoredError1 = serializer.submitAsync(secondCallable, directExecutor());

        String a,
        int b,
        // oneConstantOnly doesn't matter since it's not nullable and can be only 1 value.
        @SuppressWarnings("unused") OneConstantEnum oneConstantOnly,
        // noConstant doesn't matter since it can only be null
        @SuppressWarnings("unused") @Nullable NoConstantEnum noConstant) {
      return new GoodEquals(a, b);
    }

    // instance method ignored
    public Object badIgnored() {