old_contents: import drogher
  
  
  class TestDrogher:
      def test_dhl_barcode(self):
          package = drogher.barcode('1656740256')
          assert package.shipper == 'DHL'
  
      def test_fedex_express_barcode(self):
          package = drogher.barcode('9632001960000000000400152152152158')
          assert package.shipper == 'FedEx'
  
      def test_fedex_ground96_barcode(self):
          package = drogher.barcode('9611019012345612345671')
          assert package.shipper == 'FedEx'
  
      def test_ontrac_barcode(self):
          package = drogher.barcode('D10010945303074')
          assert package.shipper == 'OnTrac'
  
      def test_ups_barcode(self):
          package = drogher.barcode('1Z999AA10123456784')
          assert package.shipper == 'UPS'
  
      def test_uspsimpb_barcode(self):
          package = drogher.barcode('420221539101026837331000039521')
          assert package.shipper == 'USPS'
  
      def test_uspss10_barcode(self):
          package = drogher.barcode('EF123456785US')
          assert package.shipper == 'USPS'
  
      def test_invalid_barcode(self):
          package = drogher.barcode('1234')
          assert package.shipper is None
  
      def test_barcode_classes(self):
          package = drogher.barcode('EF123456785US', barcode_classes=['DHL'])
          assert package.shipper is None
          package = drogher.barcode('1656740256', barcode_classes=['DHL'])
          assert package.shipper == 'DHL'
  
new_contents: import drogher
  
  
  class TestDrogher:
      def test_dhl_barcode(self):
          package = drogher.barcode('1656740256')
          assert package.shipper == 'DHL'
  
      def test_fedex_express_barcode(self):
          package = drogher.barcode('9632001960000000000400152152152158')
          assert package.shipper == 'FedEx'
  
      def test_fedex_ground96_barcode(self):
          package = drogher.barcode('9611019012345612345671')
          assert package.shipper == 'FedEx'
  
      def test_ontrac_barcode(self):
          package = drogher.barcode('D10010945303074')
          assert package.shipper == 'OnTrac'
  
      def test_ups_barcode(self):
          package = drogher.barcode('1Z999AA10123456784')
          assert package.shipper == 'UPS'
  
      def test_uspsimpb_barcode(self):
          package = drogher.barcode('420221539101026837331000039521')
          assert package.shipper == 'USPS'
  
      def test_uspss10_barcode(self):
          package = drogher.barcode('EF123456785US')
          assert package.shipper == 'USPS'
  
      def test_usps20_barcode(self):
          package = drogher.barcode('71123456789123456787')
          assert package.shipper == 'USPS'
  
      def test_invalid_barcode(self):
          package = drogher.barcode('1234')
          assert package.shipper is None
  
      def test_barcode_classes(self):
          package = drogher.barcode('EF123456785US', barcode_classes=['DHL'])
          assert package.shipper is None
          package = drogher.barcode('1656740256', barcode_classes=['DHL'])
          assert package.shipper == 'DHL'
  
subject: Add barcode test for USPS20 barcodes