import org.jspecify.annotations.NullUnmarked;

/**
 * Class that contains nested abstract tests for filtered collection views, along with their
 * implementation helpers.
 *
 * @author Louis Wasserman
 */
/*
 * TODO(cpovirk): Should all the tests for filtered collections run under GWT, too? Currently, they
 * don't.
 */
@NullUnmarked
public final class FilteredCollectionsTestUtil {
  private static final Predicate<Integer> EVEN =

      case 1:
        Entry<? extends K, ? extends V> entry = getOnlyElement(entries);
        return of((K) entry.getKey(), (V) entry.getValue());
      default:
        @SuppressWarnings("unchecked") // TODO(cpovirk): Consider storing an Entry<?, ?>[].
        Entry<K, V>[] entryArray = entries.toArray((Entry<K, V>[]) new Entry<?, ?>[entries.size()]);
        return new RegularImmutableMap<K, V>(throwIfDuplicateKeys, entryArray);
    }

            new TestStringSortedMapGenerator() {
              @Override
              protected SortedMap<String, String> create(Entry<String, String>[] entries) {
                /*
                 * TODO(cpovirk): it would be nice to create an input Map and use
                 * the copy constructor here and in the other tests
                 */
                return populate(new TreeMap<String, String>(), entries);

   */
  protected void shutDown() throws Exception {}

  /**
   * Returns the {@link Scheduler} object used to configure this service. This method will only be
   * called once.
   */
  // TODO(cpovirk): @ForOverride
  protected abstract Scheduler scheduler();

  /**
   * Returns the {@link ScheduledExecutorService} that will be used to execute the {@link #startUp},

   * methods to accept null. We could avoid having unchecked casts in Converter.java itself if we
   * could perform a cast to LegacyConverter, but we can't because it's an internal-only class.
   *
   * TODO(cpovirk): So make it part of the open-source build, albeit package-private there?
   *
   * So we use uncheckedCastNullableTToT here. This is a weird usage of that method: The method is

   */
  protected void shutDown() throws Exception {}

  /**
   * Returns the {@link Scheduler} object used to configure this service. This method will only be
   * called once.
   */
  // TODO(cpovirk): @ForOverride
  protected abstract Scheduler scheduler();

  /**
   * Returns the {@link ScheduledExecutorService} that will be used to execute the {@link #startUp},

            .longValue(),
        /* actual= */ LongMath.MAX_POWER_OF_SQRT2_UNSIGNED);
  }

  @GwtIncompatible // BigIntegerMath // TODO(cpovirk): GWT-enable BigIntegerMath
  public void testMaxLog10ForLeadingZeros() {
    for (int i = 0; i < Long.SIZE; i++) {
      assertEquals(
          BigIntegerMath.log10(BigInteger.ONE.shiftLeft(Long.SIZE - i), FLOOR),

    HashTestUtils.assertInvariants(Hashing.fingerprint2011());
    assertEquals("Hashing.fingerprint2011()", Hashing.fingerprint2011().toString());
  }

  @AndroidIncompatible // slow TODO(cpovirk): Maybe just reduce iterations under Android.
  public void testGoodFastHash() {
    for (int i = 1; i < 200; i += 17) {
      HashFunction hasher = Hashing.goodFastHash(i);
      assertTrue(hasher.bits() >= i);

    new ClassSanityTester().forAllPublicStaticMethods(Functions.class).testNulls();
  }

  @J2ktIncompatible
  @GwtIncompatible // reflection
  @AndroidIncompatible // TODO(cpovirk): ClassNotFoundException: com.google.common.base.Function
  // (I suspect that this and the other similar failures happen with ArbitraryInstances proxies.)
  public void testEqualsAndSerializable() throws Exception {

   * bufferSize ≥ k, then we can ignore any elements greater than this value.
   */
  private @Nullable T threshold;

  @SuppressWarnings("unchecked") // TODO(cpovirk): Consider storing Object[] instead of T[].
  private TopKSelector(Comparator<? super T> comparator, int k) {
    this.comparator = checkNotNull(comparator, "comparator");
    this.k = k;