code: public Comment addComment(String photoId, String commentText) throws JinxException {
      JinxUtils.validateParams(photoId, commentText);
      Map<String, String> params = new TreeMap<>();
      params.put("method", "flickr.photos.comments.addComment");
      params.put("photo_id", photoId);
      params.put("comment_text", commentText);
      return jinx.flickrPost(params, Comment.class);
    }
docs: Add comment to a photo as the currently authenticated user.
  <br>
  This method requires authentication with 'write' permission.
  
  @param photoId     (Required) The id of the photo to add a comment to.
  @param commentText (Required) Text of the comment.
  @return object containing information about the newly added comment.
  @throws JinxException if required parameters are missing, or if there are any errors.
  @see <a href="https://www.flickr.com/services/api/flickr.photos.comments.addComment.html">flickr.photos.comments.addComment</a>