For each availability zone, get the count of current instance
        reservations of each instance type. Return as a nested
        dict of AZ name to dict of instance type to reservation count.

        :rtype: dict

def _get_reserved_instance_count(self):
        """
        For each availability zone, get the count of current instance
        reservations of each instance type. Return as a nested
        dict of AZ name to dict of instance type to reservation count.

        :rtype: dict
        """
        reservations = defaultdict(int)
        az_to_res = {}
        logger.debug("Getting reserved instance information")
        res = self.conn.describe_reserved_instances()

        for x in res['ReservedInstances']:
            if x['State'] != 'active':
                logger.debug("Skipping ReservedInstance %s with state %s",
                             x['ReservedInstancesId'], x['State'])
                continue
            if 'AvailabilityZone' not in x:
                # "Regional Benefit" AZ-less reservation
                x['AvailabilityZone'] = RI_NO_AZ
            if x['AvailabilityZone'] not in az_to_res:
                az_to_res[x['AvailabilityZone']] = deepcopy(reservations)
            az_to_res[x['AvailabilityZone']][
                x['InstanceType']] += x['InstanceCount']
        # flatten and return
        for x in az_to_res:
            az_to_res[x] = dict(az_to_res[x])
        return az_to_res