### Question:
Tuple1OfNullablesMapperImpl extends AbstractTupleMapper<T, Tuple1OfNullables<T0>> implements TupleMapper<T, Tuple1OfNullables<T0>> { @Override public Tuple1OfNullables<T0> apply(T t) { return TuplesOfNullables.ofNullables( get0().apply(t) ); } Tuple1OfNullablesMapperImpl(Function<T, T0> m0); @Override Tuple1OfNullables<T0> apply(T t); Function<T, T0> get0();  }### Answer:
@Test void apply() { assertEquals(TuplesOfNullables.ofNullables(0), instance.apply(0)); }