docs: public void isNotEqualToDefaultInstance() {
      if (actual() != null && actual().equals(actual().getDefaultInstanceForType())) {
        failWithoutActual(
            simpleFact(
                lenientFormat(
                    "Not true that (%s) %s is not a default proto instance. It has no set values.",
                    actual().getClass().getName(), actualAsString())));
      }
    }