async def connect(self):
        await self.accept()

        # This actually subscribes the requesting socket to the
        # named group:
        group_name = self._get_user_group()
        if group_name:
            await self.channel_layer.group_add(
                group_name,
                self.channel_name,
            )

def _get_user_group(self):
        user = self.scope.get('user', None)
        if user is not None and user.is_authenticated:
            return user.layer_name
        return ''