old_contents: import unittest
  import sys
  from test import support
  
  class PEP3131Test(unittest.TestCase):
  
      def test_valid(self):
          class T:
              ä = 1
              µ = 2 # this is a compatibility character
              蟒 = 3
              x󠄀 = 4
          self.assertEqual(getattr(T, "\xe4"), 1)
          self.assertEqual(getattr(T, "\u03bc"), 2)
          self.assertEqual(getattr(T, '\u87d2'), 3)
          self.assertEqual(getattr(T, 'x\U000E0100'), 4)
  
      def test_non_bmp_normalized(self):
          𝔘𝔫𝔦𝔠𝔬𝔡𝔢 = 1
          # On wide builds, this is normalized, but on narrow ones it is not. See
          # #12746.
          self.assertIn("Unicode", dir())
  
      def test_invalid(self):
          try:
              from test import badsyntax_3131
          except SyntaxError as s:
              self.assertEqual(str(s),
                "invalid character in identifier (badsyntax_3131.py, line 2)")
          else:
              self.fail("expected exception didn't occur")
  
  def test_main():
      support.run_unittest(PEP3131Test)
  
  if __name__=="__main__":
      test_main()
  
new_contents: import unittest
  import sys
  from test import support
  
  class PEP3131Test(unittest.TestCase):
  
      def test_valid(self):
          class T:
              ä = 1
              µ = 2 # this is a compatibility character
              蟒 = 3
              x󠄀 = 4
          self.assertEqual(getattr(T, "\xe4"), 1)
          self.assertEqual(getattr(T, "\u03bc"), 2)
          self.assertEqual(getattr(T, '\u87d2'), 3)
          self.assertEqual(getattr(T, 'x\U000E0100'), 4)
  
      def test_non_bmp_normalized(self):
          𝔘𝔫𝔦𝔠𝔬𝔡𝔢 = 1
          # On wide builds, this is normalized, but on narrow ones it is not. See
          # #12746.
          try:
              self.assertIn("𝔘𝔫𝔦𝔠𝔬𝔡𝔢", dir())
          except AssertionError:
              raise unittest.case._ExpectedFailure(sys.exc_info())
  
      def test_invalid(self):
          try:
              from test import badsyntax_3131
          except SyntaxError as s:
              self.assertEqual(str(s),
                "invalid character in identifier (badsyntax_3131.py, line 2)")
          else:
              self.fail("expected exception didn't occur")
  
  def test_main():
      support.run_unittest(PEP3131Test)
  
  if __name__=="__main__":
      test_main()
  
subject: revert unintended change