# File lib/hammer_cli_import/persistentmap.rb, line 131
    def save_persistent_maps
      maps.each do |map_sym|
        next unless @pm[map_sym].changed?
        CSV.open((File.join data_dir, "#{map_sym}-#{Time.now.utc.iso8601}.csv"), 'wb') do |csv|
          csv << (pm_csv_headers map_sym)
          @pm[map_sym].new.each do |key, value|
            key = [key] unless key.is_a? Array
            value = [value] unless value.is_a? Array
            csv << key + value + [nil]
          end
          delval = [nil] * (val_arity map_sym)
          @pm[map_sym].del.each do |key|
            key = [key] unless key.is_a? Array
            csv << key + delval + ['-']
          end
        end
      end
    end