Enforcing Output Type in TypeScript for ConnectionList

export type ConnectionList = SortedSet.SortedSet<Connection.Connection>;

export const from = (data: readonly ConnectionOutputDto[]) =>
  Effect.forEach(data, Connection.from, {
    concurrency: 'unbounded',
  }).pipe(
    Effect.map(SortedSet.fromIterable(OrderByLastMessage)),
    Effect.map((a): ConnectionList => a), // Without this, the type is SortedSet.SortedSet<Connection.Connection>
  );