code: func (s *Simulation) Service(name string, id enode.ID) node.Service {
  	simNode, ok := s.Net.GetNode(id).Node.(*adapters.SimNode)
  	if !ok {
  		return nil
  	}
  	services := simNode.ServiceMap()
  	if len(services) == 0 {
  		return nil
  	}
  	return services[name]
  }
docs: // Service returns a single Service by name on a particular node
  // with provided id.