code: def add_processor(self, processor_instance: Processor, priority=0) -> None:
          
          assert issubclass(processor_instance.__class__, Processor)
          processor_instance.priority = priority
          processor_instance.world = self
          self._processors.append(processor_instance)
          self._processors.sort(key=lambda proc: proc.priority, reverse=True)
docs: Add a Processor instance to the World.
  
          :param processor_instance: An instance of a Processor,
          subclassed from the Processor class
          :param priority: A higher number is processed first.