code: func MergeStrings(sss ...[]string) []string {
  	result := []string{}
  	seen := map[string]bool{}
  	for _, ss := range sss {
  		for _, s := range ss {
  			if seen[s] {
  				continue
  			}
  			seen[s] = true
  			result = append(result, s)
  		}
  	}
  	sort.Strings(result)
  	return result
  }
docs: // MergeStrings merges multiple string slices together into a single slice,
  // removing duplicates.