code: public BoxRequestsFile.AddCommentToFile getAddCommentRequest(String fileId, String message) {
          BoxRequestsFile.AddCommentToFile request = new BoxRequestsFile.AddCommentToFile(fileId, message, getCommentUrl(), mSession);
          return request;
      }
docs: Gets a request that adds a comment to a file
  
  @param fileId    id of the file to add the comment to
  @param message   message for the comment that will be added
  @return  request to add a comment to a file