old_contents: import unittest
  from either_or import either_or
  
  class nxppyTests(unittest.TestCase):
      """Basic tests for the NXP Read Library python wrapper."""
  
      def test_import(self):
          """Test that it can be imported"""
          import nxppy
  
      @either_or('detect')
      def test_detect_mifare_present(self):
          """Test that we can read the UID from a present Mifare card.
          
          Either this test or the "absent" test below will pass, but never both.
          """
          import nxppy
          self.assertIsInstance(nxppy.read_mifare(), str, "Card UID is not a string")
  
      @either_or('detect')
      def test_detect_mifare_absent(self):
          """Test that an absent card results in a None response.
          
          Either this test or the "present" test above will pass, but never both.
          """
          import nxppy
          self.assertIsNone(nxppy.read_mifare(), "Card UID is not None")
  
new_contents: import unittest
  from tests.either_or import either_or
  
  class nxppyTests(unittest.TestCase):
      """Basic tests for the NXP Read Library python wrapper."""
  
      def test_import(self):
          """Test that it can be imported"""
          import nxppy
  
      @either_or('detect')
      def test_detect_mifare_present(self):
          """Test that we can read the UID from a present Mifare card.
          
          Either this test or the "absent" test below will pass, but never both.
          """
          import nxppy
          reader = nxppy.Mifare()
          self.assertIsInstance(reader, nxppy.Mifare)
          self.assertIsInstance(reader.select(), str, "Card UID is not a string")
  
      @either_or('detect')
      def test_detect_mifare_absent(self):
          """Test that an absent card results in a None response.
          
          Either this test or the "present" test above will pass, but never both.
          """
          import nxppy
          reader = nxppy.Mifare()
          self.assertIsInstance(reader, nxppy.Mifare)
          self.assertIsNone(reader.select(), "Card UID is not None")
  
subject: Update tests to use class-based interface