docs: function getAllGroups(connections, options, cb) {
    var conn = connections.mongooseConnection;
    var groupsModel = models.get(conn, models.MODELNAMES.GROUPS);
    groupsModel.find().exec(function(err, groupsList) {
      if (err) {
        return cb(err);
      }
      return cb(null, groupsList || []); // Note: purposely returning empty array here for now, maybe this should be null instead?
    });
  }