docs: def get_all_current_trains(self, train_type=None, direction=None):
          """Returns all trains that are due to start in the next 10 minutes
          @param train_type: ['mainline', 'suburban', 'dart']
          """
          params = None
          if train_type:
              url = self.api_base_url + 'getCurrentTrainsXML_WithTrainType'
              params = {
                  'TrainType': STATION_TYPE_TO_CODE_DICT[train_type]
              }
          else:
              url = self.api_base_url + 'getCurrentTrainsXML'
  
          response = requests.get(
              url, params=params, timeout=10)
  
          if response.status_code != 200:
              return []
  
          trains = self._parse_all_train_data(response.content)
  
          if direction is not None:
              return self._prune_trains(trains, direction=direction)
  
          return trains