* An implementation of {@link ExecutorService#invokeAny} for {@link ListeningExecutorService}
   * implementations.
   */
  @SuppressWarnings({
    "GoodTime", // should accept a java.time.Duration
    "CatchingUnchecked", // sneaky checked exception
    "Interruption", // We copy AbstractExecutorService.invokeAny. Maybe we shouldn't: b/227335009.
  })
  @J2ktIncompatible
  @GwtIncompatible
  @ParametricNullness

  protected Map<K, V> makeEitherMap() {
    try {
      return makePopulatedMap();
    } catch (UnsupportedOperationException e) {
      return makeEmptyMap();
    }
  }

  @SuppressWarnings("CatchingUnchecked") // sneaky checked exception
  protected final boolean supportsValuesHashCode(Map<K, V> map) {
    // get the first non-null value
    Collection<V> values = map.values();
    for (V value : values) {