checkNotNull(x);
    }

    @Keep
    void primitiveOnly(int i) {}

    @Keep
    void nullableOnly(@Nullable String s) {}

    public void noParameter() {}

    @Keep
    void primitiveAndNullable(@Nullable String s, int i) {}
  }

  static class FactoryMethodReturnsNullButNotAnnotated {
    private FactoryMethodReturnsNullButNotAnnotated() {}