code: def generate_contentinfo_from_folder(self, csvwriter, rel_path, filenames):
          
          LOGGER.debug('IN process_folder ' + str(rel_path) + '     ' + str(filenames))
          from ricecooker.utils.linecook import filter_filenames, filter_thumbnail_files, chan_path_from_rel_path
  
          # WRITE TOPIC ROW
          topicrow = self.channeldir_node_to_row( rel_path.split(os.path.sep) )
          csvwriter.writerow(topicrow)
  
          # WRITE CONTENT NODE ROWS
          chan_path = chan_path_from_rel_path(rel_path, self.channeldir)
          filenames_cleaned = filter_filenames(filenames)
          # filenames_cleaned2 = filter_thumbnail_files(chan_path, filenames_cleaned, self)
          for filename in filenames_cleaned:
              path_tuple = rel_path.split(os.path.sep)
              path_tuple.append(filename)
              filerow = self.channeldir_node_to_row(path_tuple)
              csvwriter.writerow(filerow)
docs: Create a topic node row in Content.csv for the folder at `rel_path` and
          add content node rows for all the files in the `rel_path` folder.