default Stream<Optional<Object>> stream() {
        return IntStream.range(0, degree())
            .mapToObj(this::get);
    }
Returns a {@link Stream} of all values for this Tuple. If sequential, the
Stream will start with the 0:th tuple and progress upwards.

@return a {@link Stream} of all values for this Tuple
common-parent/tuple/src/main/java/com/speedment/common/tuple/TupleOfNullables.java