Mature Channel Flag

On the old GET https://api.twitch.tv/kraken/channel endpoint, there used to be a mature flag.

How do I get this flag in the Helix API? It does not appear in the doco for any endpoints.

Helix doesn’t return the mature flag.

There is a UserVoice request for this feature to be added though so vote for it if you’d like it to be added https://twitch.uservoice.com/forums/310213-developers/suggestions/38375011-mature-flag-on-get-streams-endpoint