def _password_gen(self, encoded_bytes):
        return encoded_bytes[:random.randrange(16, 64)]
Returns an F-statistic given the following:
dataset/ETHPy150Open openstack/openstack-ansible/scripts/pw-token-gen.py/CredentialGenerator._password_gen--crossover with--dataset/ETHPy150Open radlab/sparrow/src/main/python/third_party/stats.py/aF_value