@interface TestSubtype {
    /** Suppresses the assertion on {@link TypeToken#getSubtype}. */
    boolean suppressGetSubtype() default false;

    /** Suppresses the assertion on {@link TypeToken#getSupertype}. */
    boolean suppressGetSupertype() default false;
  }

  private @Nullable Method method = null;

  /** Call this in a {@link TestSubtype} public method asserting subtype relationship. */
  final <T> T isSubtype(T sub) {

    check(rule.startsWith(WILDCARD_CHAR)) {
      """Wildcard Assertion Failure: '$rule'
A wildcard rule was added with a wildcard that is not in leftmost position! We'll need to change the ${PublicSuffixDatabase::class.java.name} to handle this."""
    }
    check(rule.indexOf(WILDCARD_CHAR, 1) == -1) {
      """Wildcard Assertion Failure: '$rule'

  @interface TestSubtype {
    /** Suppresses the assertion on {@link TypeToken#getSubtype}. */
    boolean suppressGetSubtype() default false;

    /** Suppresses the assertion on {@link TypeToken#getSupertype}. */
    boolean suppressGetSupertype() default false;
  }

  private @Nullable Method method = null;

  /** Call this in a {@link TestSubtype} public method asserting subtype relationship. */
  final <T> T isSubtype(T sub) {

   * 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) {

   * Equivalent to {@link #expectMissing(Object[]) expectMissing}{@code (null)} except that the call
   * to {@code contains(null)} is permitted to throw a {@code NullPointerException}.
   *
   * @param message message to use upon assertion failure
   */
  protected void expectNullMissingWhenNullUnsupported(String message) {
    try {
      assertFalse(message, actualContents().contains(null));
    } catch (NullPointerException tolerated) {

      @Override
      public int hashCode() {
        return 1;
      }
    }
  }

  private static void assertContains(String expectedSubstring, String actual) {
    // TODO(kevinb): use a Truth assertion here
    if (!actual.contains(expectedSubstring)) {
      fail("expected <" + actual + "> to contain <" + expectedSubstring + ">");
    }
  }

      @Override
      public int hashCode() {
        return 1;
      }
    }
  }

  private static void assertContains(String expectedSubstring, String actual) {
    // TODO(kevinb): use a Truth assertion here
    if (!actual.contains(expectedSubstring)) {
      fail("expected <" + actual + "> to contain <" + expectedSubstring + ">");
    }
  }

    // 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()) {

    }
  }

  /** Returns the product of {@code n1} exclusive through {@code n2} inclusive. */
  @SuppressWarnings("UseCorrectAssertInTests") // TODO(b/345814817): Remove or convert assertion.
  private static BigInteger oldSlowFactorial(int n1, int n2) {
    assert n1 <= n2;
    if (IntMath.log2(n2, CEILING) * (n2 - n1) < Long.SIZE - 1) {
      // the result will definitely fit into a long
      long result = 1;

   * 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) {