}

  private void expectReturnsTrue(Target target) {
    String message = Platform.format("retainAll(%s) should return true", target);
    assertTrue(message, collection.retainAll(target.toRetain));
  }

  private void expectReturnsFalse(Target target) {
    String message = Platform.format("retainAll(%s) should return false", target);
    assertFalse(message, collection.retainAll(target.toRetain));
  }

        List<E> resultsForStrategy = new ArrayList<>();
        strategy.forEach(spliteratorSupplier.get(), resultsForStrategy::add);

        // TODO(cpovirk): better failure messages
        if ((characteristics & Spliterator.NONNULL) != 0) {
          assertFalse(resultsForStrategy.contains(null));
        }
        if ((characteristics & Spliterator.SORTED) != 0) {

  static final Integer NODE_NOT_IN_GRAPH = 1000;

  // TODO(user): Consider separating Strings that we've defined here to capture
  // identifiable substrings of expected error messages, from Strings that we've defined
  // here to provide error messages.
  // TODO(user): Some Strings used in the subclasses can be added as static Strings
  // here too.
  static final String ERROR_MODIFIABLE_SET = "Set returned is unexpectedly modifiable";

  }

  private void expectReturnsTrue(Target target) {
    String message = Platform.format("retainAll(%s) should return true", target);
    assertTrue(message, collection.retainAll(target.toRetain));
  }

  private void expectReturnsFalse(Target target) {
    String message = Platform.format("retainAll(%s) should return false", target);
    assertFalse(message, collection.retainAll(target.toRetain));
  }

      return conflictingStackTrace;
    }

    /**
     * Appends the chain of messages from the {@code conflictingStackTrace} to the original {@code
     * message}.
     */
    @Override
    public String getMessage() {
      // requireNonNull is safe because ExampleStackTrace sets a non-null message.
      StringBuilder message = new StringBuilder(requireNonNull(super.getMessage()));

 *
 * @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.

  static final String EDGE_NOT_IN_GRAPH = "edgeNotInGraph";

  // TODO(user): Consider separating Strings that we've defined here to capture
  // identifiable substrings of expected error messages, from Strings that we've defined
  // here to provide error messages.
  // TODO(user): Some Strings used in the subclasses can be added as static Strings
  // here too.
  static final String ERROR_PARALLEL_EDGE = "connected by a different edge";

  static final String EDGE_NOT_IN_GRAPH = "edgeNotInGraph";

  // TODO(user): Consider separating Strings that we've defined here to capture
  // identifiable substrings of expected error messages, from Strings that we've defined
  // here to provide error messages.
  // TODO(user): Some Strings used in the subclasses can be added as static Strings
  // here too.
  static final String ERROR_PARALLEL_EDGE = "connected by a different edge";

 *
 * @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.

  private static class Sha512Holder {
    static final HashFunction SHA_512 =
        new MessageDigestHashFunction("SHA-512", "Hashing.sha512()");
  }

  /**
   * Returns a hash function implementing the Message Authentication Code (MAC) algorithm, using the
   * MD5 (128 hash bits) hash function and the given secret key.
   *
   * <p>If you are designing a new system that needs HMAC, prefer {@link #hmacSha256} or other