json.data_sets do
  json.array! @data_sets do |set|
    json.id set.id
    json.title set.title
    json.author set.author.real_name
    json.created_on set.created_on
    json.filesize number_to_human_size(set.filesize)
    json.file_path "#{@absolute_folder}/#{set.relative_path_filename}"
  end
end
json.data_sets_count @data_count