async def METHOD_NAME(
    storage: StorageControllers, ev: EventBase, user_id: str
) -> Dict[str, str]:
    ctx: Dict[str, str] = {}
    if ev.internal_metadata.outlier:
        # We don't have state for outliers, so we can't compute the context
        # except for invites and knocks. (Such events are known as 'out-of-band
        # memberships' for the user).
        if ev.type != EventTypes.Member:
            return ctx
        # We might be able to pull out the display name for the sender straight
        # from the membership event
        event_display_name = ev.content.get("displayname")
        if event_display_name and ev.state_key == ev.sender:
            ctx["sender_display_name"] = event_display_name
        room_state = []
        if ev.content.get("membership") == Membership.INVITE:
            room_state = ev.unsigned.get("invite_room_state", [])
        elif ev.content.get("membership") == Membership.KNOCK:
            room_state = ev.unsigned.get("knock_room_state", [])
        # Ideally we'd reuse the logic in `calculate_room_name`, but that gets
        # complicated to handle partial events vs pulling events from the DB.
        for state_dict in room_state:
            type_tuple = (state_dict["type"], state_dict.get("state_key"))
            if type_tuple == (EventTypes.Member, ev.sender):
                display_name = state_dict["content"].get("displayname")
                if display_name:
                    ctx["sender_display_name"] = display_name
            elif type_tuple == (EventTypes.Name, ""):
                room_name = state_dict["content"].get("name")
                if room_name:
                    ctx["name"] = room_name
        return ctx
    room_state_ids = await storage.state.get_state_ids_for_event(ev.event_id)
    # we no longer bother setting room_alias, and make room_name the
    # human-readable name instead, be that m.room.name, an alias or
    # a list of people in the room
    name = await calculate_room_name(
        storage.main, room_state_ids, user_id, fallback_to_single_member=False
    )
    if name:
        ctx["name"] = name
    sender_state_event_id = room_state_ids[("m.room.member", ev.sender)]
    sender_state_event = await storage.main.get_event(sender_state_event_id)
    ctx["sender_display_name"] = name_from_member_event(sender_state_event)
    return ctx