groupKey

Immutable. Google Group id whose members are subject to this binding's restrictions. See "id" in the G Suite Directory API's Groups resource (https://developers.google.com/admin-sdk/directory/v1/reference/groups#resource). If a group's email address/alias is changed, this resource will continue to point at the changed group. This field does not accept group email addresses or aliases. Example: "01d520gv4vjcrht"