code: func (s *Simulation) SetNodeItem(id enode.ID, key interface{}, value interface{}) {
  	s.mu.Lock()
  	defer s.mu.Unlock()
  
  	s.buckets[id].Store(key, value)
  }
docs: // SetNodeItem sets a new item associated with the node with provided NodeID.
  // Buckets should be used to avoid managing separate simulation global state.