Tuple0MapperImpl extends AbstractTupleMapper<T, Tuple0> implements TupleMapper<T, Tuple0> { @Override public Tuple0 apply(T t) { return Tuples.of( ); } private  Tuple0MapperImpl(); @Override Tuple0 apply(T t); static final Tuple0MapperImpl<?> EMPTY_MAPPER; }
@Test void apply() { assertEquals(Tuples.of(), instance.apply(0)); }