'== and != are implemented correctly.'

def test_equality(self):

    project_state = ProjectState()
    project_state.add_model(ModelState('migrations', 'Tag', [('id', models.AutoField(primary_key=True)), ('name', models.CharField(max_length=100)), ('hidden', models.BooleanField())], {}, None))
    project_state.apps
    other_state = project_state.clone()
    self.assertEqual(project_state, project_state)
    self.assertEqual(project_state, other_state)
    self.assertIs((project_state != project_state), False)
    self.assertIs((project_state != other_state), False)
    self.assertNotEqual(project_state.apps, other_state.apps)
    project_state = ProjectState()
    project_state.add_model(ModelState('migrations', 'Tag', [('id', models.AutoField(primary_key=True)), ('name', models.CharField(max_length=99)), ('hidden', models.BooleanField())], {}, None))
    self.assertNotEqual(project_state, other_state)
    self.assertIs((project_state == other_state), False)
