OptionalConverter implements PropertyConverter<Optional> { @Override public int hashCode(){ return getClass().hashCode(); }  @Override Optional convert(String value, ConversionContext ctx); @Override boolean equals(Object o); @Override int hashCode();  }
@Test public void testHashCode() { OptionalConverter instance = new OptionalConverter(); assertThat(instance.hashCode()).isEqualTo(OptionalConverter.class.hashCode()); }