* href="https://docs.oracle.com/javase/9/docs/api/java/util/Formatter.html#syntax">format
   * specifiers</a>, and alert you to usage errors by throwing {@link
   * java.util.IllegalFormatException}.
   *
   * <p>In certain cases, such as outputting debugging information or constructing a message to be
   * used for another unchecked exception, an exception during string formatting would serve little

  }

  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));
  }

    }
  }

  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 + ">");
    }
  }

  /**
   * Test class with valid equals and hashCode methods. Testers created with instances of this class

  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

          }
        };

    private PermittedMetaException(String message) {
      super(message);
    }

    abstract boolean isPermitted(Exception exception);

    void assertPermitted(Exception exception) {
      if (!isPermitted(exception)) {
        String message =
            "Exception "
                + exception.getClass().getSimpleName()

     * message}.
     */
    @Override
    public String getMessage() {
      // requireNonNull is safe because ExampleStackTrace sets a non-null message.
      StringBuilder message = new StringBuilder(requireNonNull(super.getMessage()));
      for (Throwable t = conflictingStackTrace; t != null; t = t.getCause()) {
        message.append(", ").append(t.getMessage());
      }

 */
@GwtCompatible(emulated = true)
@ElementTypesAreNonnullByDefault
public final class Throwables {
  private Throwables() {}

  /**
   * Throws {@code throwable} if it is an instance of {@code declaredType}. Example usage:
   *
   * <pre>
   * for (Foo foo : foos) {
   *   try {
   *     foo.bar();
   *   } catch (BarException | RuntimeException | Error t) {
   *     failure = t;
   *   }
   * }
   * if (failure != null) {

 */
@GwtCompatible(emulated = true)
@ElementTypesAreNonnullByDefault
public final class Throwables {
  private Throwables() {}

  /**
   * Throws {@code throwable} if it is an instance of {@code declaredType}. Example usage:
   *
   * <pre>
   * for (Foo foo : foos) {
   *   try {
   *     foo.bar();
   *   } catch (BarException | RuntimeException | Error t) {
   *     failure = t;
   *   }
   * }
   * if (failure != null) {

        new RuntimeException("but culottes have a tendancy to ride up!");
    final Object subscriber =
        new Object() {
          @Subscribe
          public void throwExceptionOn(String message) {
            throw exception;
          }
        };
    eventBus.register(subscriber);
    eventBus.post(EVENT);

    assertEquals("Cause should be available.", exception, handler.exception);

        new RuntimeException("but culottes have a tendancy to ride up!");
    final Object subscriber =
        new Object() {
          @Subscribe
          public void throwExceptionOn(String message) {
            throw exception;
          }
        };
    eventBus.register(subscriber);
    eventBus.post(EVENT);

    assertEquals("Cause should be available.", exception, handler.exception);