          # Are the tables gone?
          self.assertTableNotExists("migrations_author")
          self.assertTableNotExists("migrations_book")
  
      @override_settings(MIGRATION_MODULES={"migrations": "migrations.test_migrations", "sessions": "migrations.test_migrations_2"})
      def test_empty_plan(self):
          """
          Tests that re-planning a full migration of a fully-migrated set doesn't
          perform spurious unmigrations and remigrations.
  
 
</s> remove     available_apps = ["migrations", "django.contrib.sessions"]
 </s> add     available_apps = ["migrations", "migrations2"] </s> remove         executor.recorder.record_unapplied("sessions", "0001_initial")
 </s> add         executor.recorder.record_unapplied("migrations2", "0001_initial") </s> remove         # We use 'sessions' here as the second app as it's always present
        # in INSTALLED_APPS, so we can happily assign it test migrations.
 </s> add  </s> remove         plan = executor.migration_plan([("migrations", "0002_second"), ("sessions", "0001_initial")])
 </s> add         plan = executor.migration_plan([
            ("migrations", "0002_second"),
            ("migrations2", "0001_initial"),
        ])
    @override_settings(MIGRATION_MODULES={
        "migrations": "migrations.test_migrations",
        "migrations2": "migrations2.test_migrations_2",
    })
          # Are the tables gone?
          self.assertTableNotExists("migrations_author")
          self.assertTableNotExists("migrations_book")
  
    @override_settings(MIGRATION_MODULES={
        "migrations": "migrations.test_migrations",
        "migrations2": "migrations2.test_migrations_2",
    })
      def test_empty_plan(self):
          """
          Tests that re-planning a full migration of a fully-migrated set doesn't
          perform spurious unmigrations and remigrations.
  
keep keep keep keep replace keep keep keep keep keep
 Removed usaged of contrib.sessions as a placeholder in migration tests.

Without this, we're unable to add actual migrations for the app. 
tests/migrations/test_executor.py