code: def _get_reserved_instance_count(self):
          
          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
docs: 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