code: func join(paths ...string) string {
  	var joined string
  
  	for i, path := range paths {
  		joined = joined + path
  		if i != len(paths)-1 && !strings.HasSuffix(path, string(sep)) {
  			joined = joined + string(sep)
  		}
  	}
  
  	return joined
  }
docs: // join joins path elements together via the separator "sep" and produces valid
  // paths without multiple separators (unless multiple separators were included
  // in the original paths []string).