Consider situation with removing elements from set/dict while iterating

[pfalcon]

s = {x for x in range(10)}

for e in s:
    print(e)
    if e == 5:
        s.remove(e)

in CPython leads too:

Traceback (most recent call last):
  File "set-rem.py", line 4, in <module>
    for e in s:
RuntimeError: Set changed size during iteration

In MicroPython, it doesn't. But consider if any guarantees can be given about the result.