code: func removeOldMember(old []*memberState, name string) []*memberState {
  	for i, m := range old {
  		if m.Name == name {
  			n := len(old)
  			old[i], old[n-1] = old[n-1], nil
  			return old[:n-1]
  		}
  	}
  
  	return old
  }
docs: // removeOldMember is used to remove an old member from a list of old
  // members.