def _invalid_indexer(self, form, key):
        raise TypeError("cannot do {form} indexing on {klass} with these "
                        "indexers [{key}] of {kind}".format(
                            form=form, klass=type(self), key=key,
                            kind=type(key)))
Returns AF_INET4 or AF_INET6 depending on where to connect to.
dataset/ETHPy150Open pydata/pandas/pandas/indexes/base.py/Index._invalid_indexer--crossover with--dataset/ETHPy150Open Eforcers/gae-flask-todo/lib/werkzeug/serving.py/select_ip_version