def TestStatistic(self, data):
        group1, group2 = data
        test_stat = abs(group1.mean() - group2.mean())
        return test_stat
Get metadata for the specified aggregate.
dataset/ETHPy150Open AllenDowney/CompStats/hypothesis.py/DiffMeansPermute.TestStatistic--crossover with--dataset/ETHPy150Open BU-NU-CLOUD-SP16/Trusted-Platform-Module-nova/nova/db/api.py/aggregate_metadata_get