Consider:
from very_long_module_name import SuperLongClassName #@UnusedImport -- long string of comments which wrap over
Running isort on it using -m4 and forcing the use of parentheses renders this incorrect code:
from very_long_module_name import (
SuperLongClassName # @UnusedImport -- long string of comments which wrap over))))
(Note that isort added the ) after the comment, which generated an syntactically invalid file).