code: def _subscribed_event_count(self) -> int:
          
          event_counter = Counter()  # type: Dict[Any, int]
  
          for key, values in self._events.items():
              event_counter[key] = len(values)
  
          return sum(event_counter.values())
docs: Returns the total amount of subscribed events.
  
          :return: Integer amount events.
          :rtype: int