old_contents: import unittest
  
  from construct.lib.container import Container
  
  class TestContainer(unittest.TestCase):
  
      def test_in(self):
          c = Container(a=1)
          self.assertTrue("a" in c)
  
      def test_not_in(self):
          c = Container()
          self.assertTrue("a" not in c)
  
new_contents: import unittest
  
  from construct.lib.container import Container
  
  class TestContainer(unittest.TestCase):
  
      def test_eq_eq(self):
          c = Container(a=1)
          d = Container(a=1)
          self.assertEqual(c, d)
  
      def test_ne_wrong_type(self):
          c = Container(a=1)
          d = {"a": 1}
          self.assertNotEqual(c, d)
  
      def test_bool_false(self):
          c = Container()
          self.assertFalse(c)
  
      def test_bool_true(self):
          c = Container(a=1)
          self.assertTrue(c)
  
      def test_in(self):
          c = Container(a=1)
          self.assertTrue("a" in c)
  
      def test_not_in(self):
          c = Container()
          self.assertTrue("a" not in c)
  
subject: Test more of Container.