* the call to {@code contains(null)} is permitted to throw a {@code NullPointerException}.
   *
   * @param message message to use upon assertion failure
   */
  protected void expectNullKeyMissingWhenNullKeysUnsupported(String message) {
    try {
      assertFalse(message, getMap().containsKey(null));
    } catch (NullPointerException tolerated) {

    // We use this somewhat weird pattern with an enum for each assertion we want to make as a way
    // of dealing with the fact that one of the assertions is @GwtIncompatible but we don't want to
    // have to have duplicate @GwtIncompatible test methods just to make that assertion.
    for (AssertFailsToDecodeStrategy strategy : AssertFailsToDecodeStrategy.values()) {

   * the call to {@code contains(null)} is permitted to throw a {@code NullPointerException}.
   *
   * @param message message to use upon assertion failure
   */
  protected void expectNullKeyMissingWhenNullKeysUnsupported(String message) {
    try {
      assertFalse(message, getMap().containsKey(null));
    } catch (NullPointerException tolerated) {

  EXPECT_NE(TF_GetCode(status.get()), TF_CANCELLED);
  EXPECT_EQ(TF_GetCode(status.get()), TF_INVALID_ARGUMENT);
  EXPECT_THAT(TF_Message(status.get()), HasSubstr("assertion failed"));

  // Note that future collectives with the same context do not work at the
  // moment; once canceled, the collective executor requires the program to be
  // restarted / context to be reset.
}

    // is cancelled.
    future1.cancel(false);

    // Give the second task a chance to (incorrectly) start up while the first task is running.
    // (This is the assertion that fails.)
    assertThat(future2.isDone()).isFalse();

    // Stop the first task. The second task should then run.
    blockingCallable.stop();
    executor.shutdown();

 *
 * @param <K> the type of keys used by the maps under test
 * @param <V> the type of mapped values used the maps under test
 * @author George van den Driessche
 */
// TODO: Descriptive assertion messages, with hints as to probable fixes.
// TODO: Add another constructor parameter indicating whether the class under test is ordered, and
// check the order if so.
// TODO: Refactor to share code with SetTestBuilder etc.

    return "z";
  }

  @Override
  protected String getValueNotInPopulatedMap() throws UnsupportedOperationException {
    return "26";
  }

  /** Helper assertion comparing two maps */
  private void assertMapsEqual(Map<?, ?> expected, Map<?, ?> map) {
    assertEquals(expected, map);
    assertEquals(expected.hashCode(), map.hashCode());

    // We use this somewhat weird pattern with an enum for each assertion we want to make as a way
    // of dealing with the fact that one of the assertions is @GwtIncompatible but we don't want to
    // have to have duplicate @GwtIncompatible test methods just to make that assertion.
    for (AssertFailsToDecodeStrategy strategy : AssertFailsToDecodeStrategy.values()) {

    assertThat(e).hasMessageThat().contains("toString representation");
  }

  private static void assertErrorMessage(Throwable e, String message) {
    // TODO(kevinb): use a Truth assertion here
    if (!e.getMessage().contains(message)) {
      fail("expected <" + e.getMessage() + "> to contain <" + message + ">");
    }
  }

  /**

    return "z";
  }

  @Override
  protected String getValueNotInPopulatedMap() throws UnsupportedOperationException {
    return "26";
  }

  /** Helper assertion comparing two maps */
  private void assertMapsEqual(Map<?, ?> expected, Map<?, ?> map) {
    assertEquals(expected, map);
    assertEquals(expected.hashCode(), map.hashCode());