code: func (s *ToxicStub) Run(toxic *ToxicWrapper) {
  	s.running = make(chan struct{})
  	defer close(s.running)
  	if rand.Float32() < toxic.Toxicity {
  		toxic.Pipe(s)
  	} else {
  		new(NoopToxic).Pipe(s)
  	}
  }
docs: // Begin running a toxic on this stub, can be interrupted.
  // Runs a noop toxic randomly depending on toxicity