1. Subscription 1:, Event: 0
    2. Subscription 1:, Event: 1
    3. Subscription 2:, Event: 1
    4. Subscription 1:, Event: 2
    5. Subscription 1:, Event: 3
    6. Subscription 2:, Event: 3
    7. Subscription 3:, Event: 3
    8. Subscription 1:, Event: 4
    9. Subscription 2:, Event: 4
    11. Subscription 2:, Event: 5
    12. Subscription 3:, Event: 5
    13. Subscription 1:, Event: 6
    14. Subscription 2:, Event: 6
    15. ...