def METHOD_NAME(patched_enginemanager):
    assigned_keys = []
    service = SyncbackService(
        syncback_id=0, process_number=0, total_processes=2, num_workers=2
    )
    assert service.keys == [0, 2, 4]
    assigned_keys.extend(service.keys)
    service = SyncbackService(
        syncback_id=0, process_number=1, total_processes=2, num_workers=2
    )
    assert service.keys == [1, 3, 5]
    assigned_keys.extend(service.keys)
    # All keys are assigned (therefore all accounts are assigned)
    assert set(engine_manager.engines.keys()) == set(assigned_keys)
    # No key is assigned more than once (and therefore, no account)
    assert len(assigned_keys) == len(set(assigned_keys))