### Question:
DefaultHandler implements IAssessmentHandler { @Override public String populateAnswer(String answer) { return answer; } private  DefaultHandler(); static IAssessmentHandler getInstance(); @Override String populateQuestion(String body); @Override String populateAnswer(String answer);  }### Answer:
@Test public void populateVSAAnswer() throws Exception { handler = AssessmentItemFactory.getHandler("reference"); String passedAnswerString = "Answer"; String answerString = handler.populateAnswer(passedAnswerString); Assert.assertNotNull(answerString); Assert.assertTrue(StringUtils.isNoneBlank(answerString)); Assert.assertTrue(StringUtils.equals(passedAnswerString, answerString)); }
@Test public void populateSAAnswer() throws Exception { handler = AssessmentItemFactory.getHandler("reference"); String answerString = handler.populateAnswer(null); Assert.assertNull(answerString); }