code: def find_usage(self):
          
          logger.debug("Checking usage for service %s", self.service_name)
          for lim in self.limits.values():
              lim._reset_usage()
          elb_usage = self._find_usage_elbv1()
          alb_usage = self._find_usage_elbv2()
          logger.debug('ELBs in use: %d, ALBs in use: %d', elb_usage, alb_usage)
          self.limits['Active load balancers']._add_current_usage(
              (elb_usage + alb_usage),
              aws_type='AWS::ElasticLoadBalancing::LoadBalancer',
          )
          self._have_usage = True
          logger.debug("Done checking usage.")
docs: Determine the current usage for each limit of this service,
          and update corresponding Limit via
          :py:meth:`~.AwsLimit._add_current_usage`.