old_contents: # from ..delayed_assert import expect, assert_expectations
  
  from delayed_assert import expect, assert_expectations
  
  
  class TestDelayedAssert:
   
      def test_should_pass(self):
          expect(1 == 1, 'one is one')
          assert_expectations()
   
      def test_should_fail(self):
          expect(1 == 2)
          x = 1
          y = 2
          expect(x == y, 'x:%s y:%s' % (x,y))
          expect(1 == 1)
          assert_expectations()
  
new_contents: # from ..delayed_assert import expect, assert_expectations
  import unittest
  from delayed_assert import expect, assert_expectations
  
  
  class TestDelayedAssert(unittest.TestCase):
   
      def test_should_pass(self):
          expect(1 == 1, 'one is one')
          assert_expectations()
   
      def test_should_fail(self):
          expect(1 == 2)
          x = 1
          y = 2
          expect(x == y, 'x:%s y:%s' % (x,y))
          expect(1 == 1)
          assert_expectations()
  
subject: implement unittest