code: func Merge(labels1, labels2 Set) Set {
  	mergedMap := Set{}
  
  	for k, v := range labels1 {
  		mergedMap[k] = v
  	}
  	for k, v := range labels2 {
  		mergedMap[k] = v
  	}
  	return mergedMap
  }
docs: // Merge combines given maps, and does not check for any conflicts
  // between the maps. In case of conflicts, second map (labels2) wins