if (existingCounter.compareAndSet(oldValue, newValue)) {
          if (newValue == 0) {
            // Just CASed to 0; remove the entry to clean up the map. If the removal fails,
            // another thread has already replaced it with a new counter, which is fine.
            countMap.remove(element, existingCounter);
          }
          return oldValue;
        }
      } else {

   * will be to permit them, as it seems more likely that code would depend on that behavior than on
   * the other. Thus, we say the bug is in add(), which fails to support null.
   */
  @J2ktIncompatible
  @GwtIncompatible // reflection
  public static Method getAddNullSupportedMethod() {
    return getMethod(CollectionAddTester.class, "testAdd_nullSupported");
  }

   * will be to permit them, as it seems more likely that code would depend on that behavior than on
   * the other. Thus, we say the bug is in add(), which fails to support null.
   */
  @J2ktIncompatible
  @GwtIncompatible // reflection
  public static Method getAddNullSupportedMethod() {
    return getMethod(CollectionAddTester.class, "testAdd_nullSupported");
  }

        UnsupportedOperationException.class,
        () -> collection.removeAll(MinimalCollection.of(e0())));
    expectUnchanged();
    assertTrue(collection.contains(e0()));
  }

  /*
   * AbstractCollection fails the removeAll(null) test when the subject
   * collection is empty, but we'd still like to test removeAll(null) when we
   * can. We split the test into empty and non-empty cases. This allows us to
   * suppress only the former.

   * will be to permit them, as it seems more likely that code would depend on that behavior than on
   * the other. Thus, we say the bug is in set(), which fails to support null.
   */
  @J2ktIncompatible
  @GwtIncompatible // reflection
  public static Method getSetNullSupportedMethod() {
    return getMethod(ListSetTester.class, "testSet_null");
  }

   * will be to permit them, as it seems more likely that code would depend on that behavior than on
   * the other. Thus, we say the bug is in set(), which fails to support null.
   */
  @J2ktIncompatible
  @GwtIncompatible // reflection
  public static Method getSetNullSupportedMethod() {
    return getMethod(ListSetTester.class, "testSet_null");
  }

  }

  @CollectionFeature.Require(absent = SUPPORTS_REMOVE)
  public void testRemove_occurrences_unsupported_absent() {
    // notice: we don't care whether it succeeds, or fails with UOE
    try {
      assertEquals(
          "multiset.remove(absent, 2) didn't return 0 or throw an exception",
          0,
          getMultiset().remove(e3(), 2));

    assertThat(min(1, 2, reverse)).isEqualTo(2);
    assertThat(min(2, 1, reverse)).isEqualTo(2);
    assertThat(max(1, 2, reverse)).isEqualTo(1);
    assertThat(max(2, 1, reverse)).isEqualTo(1);
  }

  /**
   * Fails compilation if the signature of min and max is changed to take {@code Comparator<T>}
   * instead of {@code Comparator<? super T>}.
   */
  public void testMinMaxWithSupertypeComparator() {

    /* The following fails to compile:
     *
     * The method append(Iterable<? extends FluentIterableTest.A>) in the type
     * FluentIterable<FluentIterableTest.A> is not applicable for the arguments
     * (Iterable<FluentIterableTest.B>)
     */
    // FluentIterable.from(aIterable).append(bIterable);

    /* The following fails to compile:
     *

    }

    @Override
    protected Map<Integer, Character> getValueNotInPopulatedMap() {
      return ImmutableMap.of();
    }

    /**
     * The version of this test supplied by {@link MapInterfaceTest} fails for this particular map
     * implementation, because {@code map.get()} returns a view collection that changes in the
     * course of a call to {@code remove()}. Thus, the expectation doesn't hold that {@code