code: public static void fail(String description, @Nullable Throwable realCause) {
      AssertionError error = failure(description);
      error.initCause(realCause);
      throw error;
    }
docs: Throws an {@code AssertionError} with the given message and with the {@code Throwable} that caused the failure.
  
  @param description the description of the failed assertion. It can be {@code null}.
  @param realCause   cause of the error.