docs: def _spark_executor_metrics(self, instance, running_apps, addl_tags, requests_config):
          """
          Get metrics for each Spark executor.
          """
          for app_id, (app_name, tracking_url) in iteritems(running_apps):
  
              base_url = self._get_request_url(instance, tracking_url)
              response = self._rest_request_to_json(
                  base_url, SPARK_APPS_PATH, SPARK_SERVICE_CHECK, requests_config, addl_tags, app_id, 'executors'
              )
  
              tags = ['app_name:%s' % str(app_name)]
              tags.extend(addl_tags)
  
              for executor in response:
                  if executor.get('id') == 'driver':
                      self._set_metrics_from_json(tags, executor, SPARK_DRIVER_METRICS)
                  else:
                      self._set_metrics_from_json(tags, executor, SPARK_EXECUTOR_METRICS)
  
              if len(response):
                  self._set_metric('spark.executor.count', COUNT, len(response), tags)