keyedStateBackend.snapshot(checkpointId, timestamp, factory, checkpointOptions));
when(keyedStateBackend.snapshot( eq(checkpointId), eq(timestamp),
keyedStateBackend.snapshot(checkpointId, timestamp, factory, checkpointOptions));
keyedStateBackend.snapshot(checkpointId, timestamp, factory, checkpointOptions));
keyedStateBackend.snapshot(checkpointId, timestamp, factory, checkpointOptions));