    # File lib/active_support/testing/performance.rb, line 206
              def output_filename(printer_class)
                suffix =
                  case printer_class.name.demodulize
                    when 'FlatPrinter'; 'flat.txt'
                    when 'GraphPrinter'; 'graph.txt'
                    when 'GraphHtmlPrinter'; 'graph.html'
                    when 'CallTreePrinter'; 'tree.txt'
                    else printer_class.name.sub(/Printer$/, '').underscore
                  end

                "#{super()}_#{suffix}"
              end