it 'delete_all_selected_topics for a non private assignment and redirects to edit assignment page with multiple topic selected' do
      create(:topic, id: 2, assignment_id: 3, topic_identifier: 'topic2')
      create(:topic, id: 3, assignment_id: 3, topic_identifier: 'topic3')
      create(:topic, id: 8, assignment_id: 3, topic_identifier: 'topic4')
      request_params = { assignment_id: 3, topic_ids: %w[topic2 topic3] }