docs: def _standalone_init(self, spark_master_address, pre_20_mode, requests_config, tags):
          """
          Return a dictionary of {app_id: (app_name, tracking_url)} for the running Spark applications
          """
          metrics_json = self._rest_request_to_json(
              spark_master_address, SPARK_MASTER_STATE_PATH, SPARK_STANDALONE_SERVICE_CHECK, requests_config, tags
          )
  
          running_apps = {}
  
          if metrics_json.get('activeapps'):
              for app in metrics_json['activeapps']:
                  app_id = app.get('id')
                  app_name = app.get('name')
  
                  # Parse through the HTML to grab the application driver's link
                  try:
                      app_url = self._get_standalone_app_url(app_id, spark_master_address, requests_config, tags)
  
                      if app_id and app_name and app_url:
                          if pre_20_mode:
                              self.log.debug('Getting application list in pre-20 mode')
                              applist = self._rest_request_to_json(
                                  app_url, SPARK_APPS_PATH, SPARK_STANDALONE_SERVICE_CHECK, requests_config, tags
                              )
                              for appl in applist:
                                  aid = appl.get('id')
                                  aname = appl.get('name')
                                  running_apps[aid] = (aname, app_url)
                          else:
                              running_apps[app_id] = (app_name, app_url)
                  except Exception:
                      # it's possible for the requests to fail if the job
                      # completed since we got the list of apps.  Just continue
                      pass
  
          # Report success after gathering metrics from Spark master
          self.service_check(
              SPARK_STANDALONE_SERVICE_CHECK,
              AgentCheck.OK,
              tags=['url:%s' % spark_master_address] + tags,
              message='Connection to Spark master "%s" was successful' % spark_master_address,
          )
          self.log.info("Returning running apps %s" % running_apps)
          return running_apps