}

  private interface NumberList<T extends Number> {}

  public void testImplicitUpperBoundForWildcards() {
    assertAssignable(
        new TypeToken<NumberList<? extends Number>>() {}, new TypeToken<NumberList<?>>() {});
    assertAssignable(
        new TypeToken<NumberList<? super Integer>>() {}, new TypeToken<NumberList<?>>() {});
  }