def __init__(self, ops=None):
        if ops is not None:
            assert len(ops) >= 2, "DoWhile should have at least two children"
        NaryOperator.__init__(self, ops)
Test the product filtering of the readout.
dataset/ETHPy150Open uwescience/raco/raco/algebra.py/DoWhile.__init__--crossover with--dataset/ETHPy150Open mozilla/kitsune/kitsune/dashboards/tests/test_readouts.py/NeedsChangesTests.test_by_product