def min_max(buf):
    data = filter(lambda x: x <> None, buf)
    smallest = min(map(min, data))
    largest = max(map(max, data))
    return (smallest, largest)
Verify that memoized calc of Z terms stored in SS exactly match
dataset/ETHPy150Open rm-hull/pcd8544/examples/plotter.py/min_max--crossover with--dataset/ETHPy150Open daeilkim/refinery/refinery/bnpy/bnpy-dev/tests/merge/TestMathForHDPMerges.py/TestMathForHDPMerges.test_ELBO_Z_terms_are_correct_alldata