code: def _find_usage_elbv2(self):
          
          logger.debug('Checking usage for ELBv2')
          conn2 = client(
              'elbv2',
              config=Config(retries={'max_attempts': ELBV2_MAX_RETRY_ATTEMPTS}),
              **self._boto3_connection_kwargs
          )
          logger.debug("Connected to %s in region %s (with max retry attempts "
                       "overridden to %d)", 'elbv2',
                       conn2._client_config.region_name, ELBV2_MAX_RETRY_ATTEMPTS)
          # Target groups
          tgroups = paginate_dict(
              conn2.describe_target_groups,
              alc_marker_path=['NextMarker'],
              alc_data_path=['TargetGroups'],
              alc_marker_param='Marker'
          )
          self.limits['Target groups']._add_current_usage(
              len(tgroups['TargetGroups']),
              aws_type='AWS::ElasticLoadBalancingV2::TargetGroup'
          )
          # ALBs
          lbs = paginate_dict(
              conn2.describe_load_balancers,
              alc_marker_path=['NextMarker'],
              alc_data_path=['LoadBalancers'],
              alc_marker_param='Marker'
          )
          logger.debug(
              'Checking usage for each of %d ALBs', len(lbs['LoadBalancers'])
          )
          alb_count = 0
          nlb_count = 0
          for lb in lbs['LoadBalancers']:
              if lb.get('Type') == 'network':
                  nlb_count += 1
              else:
                  alb_count += 1
                  self._update_usage_for_alb(
                      conn2,
                      lb['LoadBalancerArn'],
                      lb['LoadBalancerName']
                  )
          self.limits['Network load balancers']._add_current_usage(
              nlb_count,
              aws_type='AWS::ElasticLoadBalancing::NetworkLoadBalancer'
          )
          logger.debug('Done with ELBv2 usage')
          return alb_count
docs: Find usage for ELBv2 / Application LB and update the appropriate limits.
  
          :returns: number of Application LBs in use
          :rtype: int