def METHOD_NAME(self):
    # Arrange
    activity_page = self.create_activity_detail_page(
        "Test", "test", topic_list=[6]
    )
    # Act
    actual_subtopic_ids = activity_page.get_subtopic_ids()
    # Assert
    self.assertIsInstance(actual_subtopic_ids, set)
    self.assertFalse(actual_subtopic_ids)