def do_add_streams_to_default_stream_group(realm: Realm, group: DefaultStreamGroup, streams: List[Stream]) -> None:
    default_streams = get_default_streams_for_realm(realm.id)
    for stream in streams:
        if (stream in default_streams):
            raise JsonableError(_("'{stream_name}' is a default stream and cannot be added to '{group_name}'").format(stream_name=stream.name, group_name=group.name))
        if (stream in group.streams.all()):
            raise JsonableError(_("Stream '{stream_name}' is already present in default stream group '{group_name}'").format(stream_name=stream.name, group_name=group.name))
        group.streams.add(stream)
    group.save()
    notify_default_stream_groups(realm)
def do_add_streams_to_default_stream_group(realm: Realm, group: DefaultStreamGroup, streams: List[Stream]) -> None:
    default_streams = get_default_streams_for_realm(realm.id)
    for stream in streams:
        if (stream in default_streams):
            raise JsonableError(_("'{stream_name}' is a default stream and cannot be added to '{group_name}'").format(stream_name=stream.name, group_name=group.name))
        if (stream in group.streams.all()):
            raise JsonableError(_("Stream '{stream_name}' is already present in default stream group '{group_name}'").format(stream_name=stream.name, group_name=group.name))
        group.streams.add(stream)
    group.save()
    notify_default_stream_groups(realm)