Called to store the userid for a request.

        This function creates a ticket from the request and user_id, and calls
        the abstract function remember_ticket() to store the ticket.

        Args:
            request: aiohttp Request object.
            user_id: String representing the user_id to remember

async def remember(self, request, user_id):
        """Called to store the userid for a request.

        This function creates a ticket from the request and user_id, and calls
        the abstract function remember_ticket() to store the ticket.

        Args:
            request: aiohttp Request object.
            user_id: String representing the user_id to remember
        """
        ticket = self._new_ticket(request, user_id)
        await self.remember_ticket(request, ticket)