checkNotNull(s);
    }

    public void rejectNull(String s) {
      checkNotNull(s);
    }
  }

  public static class BadNulls {
    public void failsToRejectNull(@SuppressWarnings("unused") String s) {}
  }

  public static class NoNullCheckNeededDespiteNotInstantiable {

    public NoNullCheckNeededDespiteNotInstantiable(NotInstantiable x) {