@pytest.fixture(scope='function')
def clear_checkpoints(txnPoolNodeSet):
    for node in txnPoolNodeSet:
        for (inst_id, replica) in node.replicas.items():
            replica._checkpointer._reset_checkpoints()
            replica._checkpointer._stashed_recvd_checkpoints.clear()
@pytest.fixture(scope='function')
def clear_checkpoints(txnPoolNodeSet):
    for node in txnPoolNodeSet:
        for (inst_id, replica) in node.replicas.items():
            replica._checkpointer._reset_checkpoints()
            replica._checkpointer._stashed_recvd_checkpoints.clear()