@Override
default <U> Tree<Tuple2<T, U>> zipAll(Iterable<U> that, T thisElem, U thatElem) {
Objects.requireNonNull(that, "that is null");
if (isEmpty()) {
return Iterator.ofAll(that).map(elem -> Tuple.of(thisElem, elem)).toTree();
} else {
final java.util.Iterator<U> thatIter = that.iterator();
final Tree<Tuple2<T, U>> tree = ZipAll.apply((Node<T>) this, thatIter, thatElem);
if (thatIter.hasNext()) {
final Iterable<Node<Tuple2<T, U>>> remainder =
Iterator.ofAll(thatIter).map(elem -> Tree.of(Tuple.of(thisElem, elem)));
return new Node<>(tree.getValue(), tree.getChildren().appendAll(remainder));
} else {
return tree;
}
}
}
@Override
default Tree<Tuple2<T, Integer>> zipWithIndex() {
return zip(Iterator.from(0));
}