def availability_zones(self, **query):
        return self._list(availability_zone.AvailabilityZone,
                          paginated=False, **query)
Returns a deferred whose callback will be passed the header for
dataset/ETHPy150Open openstack/python-openstacksdk/openstack/compute/v2/_proxy.py/Proxy.availability_zones--crossover with--dataset/ETHPy150Open kuri65536/python-for-android/python-modules/twisted/twisted/news/database.py/INewsStorage.headRequest