code: func (s *EventFilter) Invoke(e serf.Event) bool {
  	if s.Event == "*" {
  		return true
  	}
  
  	if e.EventType().String() != s.Event {
  		return false
  	}
  
  	if s.Event == "user" && s.Name != "" {
  		userE, ok := e.(serf.UserEvent)
  		if !ok {
  			return false
  		}
  
  		if userE.Name != s.Name {
  			return false
  		}
  	}
  
  	if s.Event == "query" && s.Name != "" {
  		query, ok := e.(*serf.Query)
  		if !ok {
  			return false
  		}
  
  		if query.Name != s.Name {
  			return false
  		}
  	}
  
  	return true
  }
docs: // Invoke tests whether or not this event script should be invoked
  // for the given Serf event.