code: private static boolean hasConstructorUsableByGetChecked(
        Class<? extends Exception> exceptionClass) {
      try {
        Exception unused = newWithCause(exceptionClass, new Exception());
        return true;
      } catch (Exception e) {
        return false;
      }
    }
docs: /*
  TODO(user): FutureChecker interface for these to be static methods on? If so, refer to it in
  the (static-method) Futures.getChecked documentation