@Override
  public MapSettings setProperty(String key, String value) {
    return (MapSettings) super.setProperty(key, value);
  }
@Test
  public void getInt_value_must_be_valid() {
    Settings settings = new MapSettings();
    settings.setProperty("foo", "not a number");

    assertThatThrownBy(() -> settings.getInt("foo"))
      .isInstanceOf(NumberFormatException.class);
  }