'Return zone object representing an EC2 availability zone
Raises exception.ZoneDoesNotExist if not successful'

def get_zone(self, zone):

    try:
        return self.get_zones(filters={'zone-name': zone})[0]
    except boto.exception.EC2ResponseError as e:
        if (e.error_code == 'InvalidZone.NotFound'):
            raise exception.ZoneDoesNotExist(zone, self.region.name)
    except IndexError:
        raise exception.ZoneDoesNotExist(zone, self.region.name)
