code: func NewKeyRenamer(patternKeys ...string) (KeyRenamer, error) {
  	var renames []keyRename
  	for i := 0; i < len(patternKeys); i += 2 {
  		g, err := glob.Compile(strings.ToLower(patternKeys[i]), '/')
  		if err != nil {
  			return KeyRenamer{}, err
  		}
  		renames = append(renames, keyRename{pattern: g, newKey: patternKeys[i+1]})
  	}
  
  	return KeyRenamer{renames: renames}, nil
  }
docs: // NewKeyRenamer creates a new KeyRenamer given a list of pattern and new key
  // value pairs.