code: func hasPathPrefix(s, prefix string) bool {
  	switch {
  	default:
  		return false
  	case len(s) == len(prefix):
  		return s == prefix
  	case len(s) > len(prefix):
  		if prefix != "" && prefix[len(prefix)-1] == '/' {
  			return strings.HasPrefix(s, prefix)
  		}
  		return s[len(prefix)] == '/' && s[:len(prefix)] == prefix
  	}
  }
docs: // hasPathPrefix reports whether the path s begins with the
  // elements in prefix.