Unexpected keyword argument "required" for "add_subparsers" of "ArgumentParser"

[igor-raits]

sgmanager/cli.py:55: error: Unexpected keyword argument "required" for "add_subparsers" of "ArgumentParser"

https://docs.python.org/3/library/argparse.html#argparse.ArgumentParser.add_subparsers

[asottile]

oh hey neat, someone is using the feature I added -- I made a PR to improve the annotation #2416