20 = note: required because of the requirements on the impl of `Iterator` for `IteratorOfWrapped<(), Map<IteratorOfWrapped<(), Map<IteratorOfWrapped<(), Map<IteratorOfWrapped<(), Map<IteratorOfWrapped<(), Map<IteratorOfWrapped<(), Map<IteratorOfWrapped<(), Map<IteratorOfWrapped<(), Map<IteratorOfWrapped<(), Map<IteratorOfWrapped<(), Map<IteratorOfWrapped<(), Map<IteratorOfWrapped<(), Map<IteratorOfWrapped<(), Map<IteratorOfWrapped<(), Map<IteratorOfWrapped<(), Map<IteratorOfWrapped<(), Map<IteratorOfWrapped<(), Map<IteratorOfWrapped<(), Map<IteratorOfWrapped<(), Map<IteratorOfWrapped<(), Map<IteratorOfWrapped<(), Map<IteratorOfWrapped<(), Map<IteratorOfWrapped<(), Map<IteratorOfWrapped<(), Map<IteratorOfWrapped<(), Map<IteratorOfWrapped<(), Map<IteratorOfWrapped<(), Map<IteratorOfWrapped<(), Map<IteratorOfWrapped<(), Map<IteratorOfWrapped<(), Map<IteratorOfWrapped<(), Map<IteratorOfWrapped<(), Map<IteratorOfWrapped<(), Map<IteratorOfWrapped<(), Map<IteratorOfWrapped<(), Map<IteratorOfWrapped<(), Map<IteratorOfWrapped<(), Map<IteratorOfWrapped<(), Map<IteratorOfWrapped<(), Map<IteratorOfWrapped<(), Map<IteratorOfWrapped<(), Map<IteratorOfWrapped<(), Map<IteratorOfWrapped<(), Map<IteratorOfWrapped<(), Map<IteratorOfWrapped<(), Map<IteratorOfWrapped<(), Map<IteratorOfWrapped<(), Map<IteratorOfWrapped<(), Map<IteratorOfWrapped<(), Map<IteratorOfWrapped<(), Map<IteratorOfWrapped<(), Map<IteratorOfWrapped<(), Map<IteratorOfWrapped<(), Map<IteratorOfWrapped<(), Map<IteratorOfWrapped<(), Map<IteratorOfWrapped<(), Map<IteratorOfWrapped<(), Map<IteratorOfWrapped<(), Map<IteratorOfWrapped<(), Map<IteratorOfWrapped<(), Map<IteratorOfWrapped<(), Map<IteratorOfWrapped<(), Map<IteratorOfWrapped<(), Map<IteratorOfWrapped<(), Map<IteratorOfWrapped<(), Map<IteratorOfWrapped<(), Map<IteratorOfWrapped<(), Map<IteratorOfWrapped<(), Map<IteratorOfWrapped<(), Map<IteratorOfWrapped<(), Map<IteratorOfWrapped<(), Map<IteratorOfWrapped<(), Map<IteratorOfWrapped<(), Map<IteratorOfWrapped<(), Map<IteratorOfWrapped<(), Map<IteratorOfWrapped<(), Map<IteratorOfWrapped<(), Map<IteratorOfWrapped<(), Map<IteratorOfWrapped<(), Map<IteratorOfWrapped<(), Map<IteratorOfWrapped<(), Map<IteratorOfWrapped<(), Map<IteratorOfWrapped<(), Map<IteratorOfWrapped<(), Map<IteratorOfWrapped<(), Map<IteratorOfWrapped<(), std::iter::Empty<()>>, [closure@$DIR/issue-91949-hangs-on-recursion.rs:26:45: 26:48]>>, [closure@$DIR/issue-91949-hangs-on-recursion.rs:26:45: 26:48]>>, [closure@$DIR/issue-91949-hangs-on-recursion.rs:26:45: 26:48]>>, [closure@$DIR/issue-91949-hangs-on-recursion.rs:26:45: 26:48]>>, [closure@$DIR/issue-91949-hangs-on-recursion.rs:26:45: 26:48]>>, [closure@$DIR/issue-91949-hangs-on-recursion.rs:26:45: 26:48]>>, [closure@$DIR/issue-91949-hangs-on-recursion.rs:26:45: 26:48]>>, [closure@$DIR/issue-91949-hangs-on-recursion.rs:26:45: 26:48]>>, [closure@$DIR/issue-91949-hangs-on-recursion.rs:26:45: 26:48]>>, [closure@$DIR/issue-91949-hangs-on-recursion.rs:26:45: 26:48]>>, [closure@$DIR/issue-91949-hangs-on-recursion.rs:26:45: 26:48]>>, [closure@$DIR/issue-91949-hangs-on-recursion.rs:26:45: 26:48]>>, [closure@$DIR/issue-91949-hangs-on-recursion.rs:26:45: 26:48]>>, [closure@$DIR/issue-91949-hangs-on-recursion.rs:26:45: 26:48]>>, [closure@$DIR/issue-91949-hangs-on-recursion.rs:26:45: 26:48]>>, [closure@$DIR/issue-91949-hangs-on-recursion.rs:26:45: 26:48]>>, [closure@$DIR/issue-91949-hangs-on-recursion.rs:26:45: 26:48]>>, [closure@$DIR/issue-91949-hangs-on-recursion.rs:26:45: 26:48]>>, [closure@$DIR/issue-91949-hangs-on-recursion.rs:26:45: 26:48]>>, [closure@$DIR/issue-91949-hangs-on-recursion.rs:26:45: 26:48]>>, [closure@$DIR/issue-91949-hangs-on-recursion.rs:26:45: 26:48]>>, [closure@$DIR/issue-91949-hangs-on-recursion.rs:26:45: 26:48]>>, [closure@$DIR/issue-91949-hangs-on-recursion.rs:26:45: 26:48]>>, [closure@$DIR/issue-91949-hangs-on-recursion.rs:26:45: 26:48]>>, [closure@$DIR/issue-91949-hangs-on-recursion.rs:26:45: 26:48]>>, [closure@$DIR/issue-91949-hangs-on-recursion.rs:26:45: 26:48]>>, [closure@$DIR/issue-91949-hangs-on-recursion.rs:26:45: 26:48]>>, [closure@$DIR/issue-91949-hangs-on-recursion.rs:26:45: 26:48]>>, [closure@$DIR/issue-91949-hangs-on-recursion.rs:26:45: 26:48]>>, [closure@$DIR/issue-91949-hangs-on-recursion.rs:26:45: 26:48]>>, [closure@$DIR/issue-91949-hangs-on-recursion.rs:26:45: 26:48]>>, [closure@$DIR/issue-91949-hangs-on-recursion.rs:26:45: 26:48]>>, [closure@$DIR/issue-91949-hangs-on-recursion.rs:26:45: 26:48]>>, [closure@$DIR/issue-91949-hangs-on-recursion.rs:26:45: 26:48]>>, [closure@$DIR/issue-91949-hangs-on-recursion.rs:26:45: 26:48]>>, [closure@$DIR/issue-91949-hangs-on-recursion.rs:26:45: 26:48]>>, [closure@$DIR/issue-91949-hangs-on-recursion.rs:26:45: 26:48]>>, [closure@$DIR/issue-91949-hangs-on-recursion.rs:26:45: 26:48]>>, [closure@$DIR/issue-91949-hangs-on-recursion.rs:26:45: 26:48]>>, [closure@$DIR/issue-91949-hangs-on-recursion.rs:26:45: 26:48]>>, [closure@$DIR/issue-91949-hangs-on-recursion.rs:26:45: 26:48]>>, [closure@$DIR/issue-91949-hangs-on-recursion.rs:26:45: 26:48]>>, [closure@$DIR/issue-91949-hangs-on-recursion.rs:26:45: 26:48]>>, [closure@$DIR/issue-91949-hangs-on-recursion.rs:26:45: 26:48]>>, [closure@$DIR/issue-91949-hangs-on-recursion.rs:26:45: 26:48]>>, [closure@$DIR/issue-91949-hangs-on-recursion.rs:26:45: 26:48]>>, [closure@$DIR/issue-91949-hangs-on-recursion.rs:26:45: 26:48]>>, [closure@$DIR/issue-91949-hangs-on-recursion.rs:26:45: 26:48]>>, [closure@$DIR/issue-91949-hangs-on-recursion.rs:26:45: 26:48]>>, [closure@$DIR/issue-91949-hangs-on-recursion.rs:26:45: 26:48]>>, [closure@$DIR/issue-91949-hangs-on-recursion.rs:26:45: 26:48]>>, [closure@$DIR/issue-91949-hangs-on-recursion.rs:26:45: 26:48]>>, [closure@$DIR/issue-91949-hangs-on-recursion.rs:26:45: 26:48]>>, [closure@$DIR/issue-91949-hangs-on-recursion.rs:26:45: 26:48]>>, [closure@$DIR/issue-91949-hangs-on-recursion.rs:26:45: 26:48]>>, [closure@$DIR/issue-91949-hangs-on-recursion.rs:26:45: 26:48]>>, [closure@$DIR/issue-91949-hangs-on-recursion.rs:26:45: 26:48]>>, [closure@$DIR/issue-91949-hangs-on-recursion.rs:26:45: 26:48]>>, [closure@$DIR/issue-91949-hangs-on-recursion.rs:26:45: 26:48]>>, [closure@$DIR/issue-91949-hangs-on-recursion.rs:26:45: 26:48]>>, [closure@$DIR/issue-91949-hangs-on-recursion.rs:26:45: 26:48]>>, [closure@$DIR/issue-91949-hangs-on-recursion.rs:26:45: 26:48]>>, [closure@$DIR/issue-91949-hangs-on-recursion.rs:26:45: 26:48]>>, [closure@$DIR/issue-91949-hangs-on-recursion.rs:26:45: 26:48]>>, [closure@$DIR/issue-91949-hangs-on-recursion.rs:26:45: 26:48]>>, [closure@$DIR/issue-91949-hangs-on-recursion.rs:26:45: 26:48]>>, [closure@$DIR/issue-91949-hangs-on-recursion.rs:26:45: 26:48]>>, [closure@$DIR/issue-91949-hangs-on-recursion.rs:26:45: 26:48]>>, [closure@$DIR/issue-91949-hangs-on-recursion.rs:26:45: 26:48]>>, [closure@$DIR/issue-91949-hangs-on-recursion.rs:26:45: 26:48]>>, [closure@$DIR/issue-91949-hangs-on-recursion.rs:26:45: 26:48]>>, [closure@$DIR/issue-91949-hangs-on-recursion.rs:26:45: 26:48]>>, [closure@$DIR/issue-91949-hangs-on-recursion.rs:26:45: 26:48]>>, [closure@$DIR/issue-91949-hangs-on-recursion.rs:26:45: 26:48]>>, [closure@$DIR/issue-91949-hangs-on-recursion.rs:26:45: 26:48]>>, [closure@$DIR/issue-91949-hangs-on-recursion.rs:26:45: 26:48]>>, [closure@$DIR/issue-91949-hangs-on-recursion.rs:26:45: 26:48]>>, [closure@$DIR/issue-91949-hangs-on-recursion.rs:26:45: 26:48]>>, [closure@$DIR/issue-91949-hangs-on-recursion.rs:26:45: 26:48]>>, [closure@$DIR/issue-91949-hangs-on-recursion.rs:26:45: 26:48]>>, [closure@$DIR/issue-91949-hangs-on-recursion.rs:26:45: 26:48]>>, [closure@$DIR/issue-91949-hangs-on-recursion.rs:26:45: 26:48]>>, [closure@$DIR/issue-91949-hangs-on-recursion.rs:26:45: 26:48]>>, [closure@$DIR/issue-91949-hangs-on-recursion.rs:26:45: 26:48]>>, [closure@$DIR/issue-91949-hangs-on-recursion.rs:26:45: 26:48]>>`