csv_for_each :category do |row|
        next if row["id"].nil? || row["id"].empty?
        group     = groups[row["group_id"]]
        category  = group.categories.find_or_initialize_by_name(row["name"]) do |m|
          m.creator = User.find(user_ids[row["creator_id"]]) if row["creator_id"].present?