watch method

Implementation

Stream<List<MapChangeNotification<SessionId, Session>>> watch() {
  return stream((db) {
    final stmt = db.select(db.sessions);
    stmt.orderBy([(u) => OrderingTerm.desc(u.lastActivatedAt)]);
    return stmt
        .watch()
        .map((rows) => {for (var e in rows.map(_SessionDb.fromDb)) e.id: e})
        .changes();
  });
}