Useful for https://github.com/CQCL/tket2/issues/632 There is some template code in #1834, but this should be changed to use `HugrMut::copy_descendants`, as #1934
Useful for Quantinuum/tket2#632
There is some template code in #1834, but this should be changed to use
HugrMut::copy_descendants, as #1934