context 'when no choices are correct' do
      it 'returns "Please select a correct answer for all questions"' do
        questions = { '1' => { txt: 'question text', iscorrect: '0' }, '2' => { txt: 'question text', iscorrect: '0' }, '3' => { txt: 'question text', iscorrect: '0' }, '4' => { txt: 'question text', iscorrect: '0' } }
        expect(multiple_choice_checkbox.isvalid(questions)).to eq('Please select a correct answer for all questions')