def test_method_in_bulk(self):
        """Not run by default testing, but can be run locally to help tune stochastic aspects of tests
        to very-very-rarely fail. EG:
        % BULK_TEST_REPS=200 METHOD_NAME=test_cbow_hs pytest test_word2vec.py -k "test_method_in_bulk"
        Method must accept `ranks` keyword-argument, empty list into which salient internal result can be reported.
        """
        failures = 0
        ranks = []
        reps = int(os.environ['BULK_TEST_REPS'])
        method_name = os.environ.get('METHOD_NAME', 'test_cbow_hs')  # by default test that specially-troublesome one
        method_fn = getattr(self, method_name)
        for i in range(reps):
            try:
                method_fn(ranks=ranks)
            except Exception as ex:
                print('%s failed: %s' % (method_name, ex))
                failures += 1
        print(ranks)
        print(np.mean(ranks))
        self.assertEquals(failures, 0, "too many failures")