code: func (s *ChangesService) ListRevisionDrafts(changeID, revisionID string) (*map[string][]CommentInfo, *Response, error) {
  	u := fmt.Sprintf("changes/%s/revisions/%s/drafts/", changeID, revisionID)
  	return s.getCommentInfoMapSliceResponse(u)
  }
docs: // ListRevisionDrafts lists the draft comments of a revision that belong to the calling user.
  // Returns a map of file paths to lists of CommentInfo entries.
  // The entries in the map are sorted by file path.
  //
  // Gerrit API docs: https://gerrit-review.googlesource.com/Documentation/rest-api-changes.html#list-drafts