context 'when only 1 choices are correct' do
      it 'returns "A multiple-choice checkbox question should have more than one correct answer."' do
        questions = { '1' => { txt: 'question text', iscorrect: '1' }, '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('A multiple-choice checkbox question should have more than one correct answer.')