docs: def end_task(self, name, success=True):
          """
          End a running task. Raises an exception if the task isn't
          running.
  
          name: The name of the task to complete.
          success: (optional, True) Whether the task was successful.
          """
          self._running.remove(name)
  
          if success:
              self._completed.add(name)
              self._graph.remove(name, strategy=Strategy.orphan)
          else:
              self._cascade_failure(name)