public String getStartTimeStr() {
    String str = NA;

    if (startTime >= 0) {
      str = new Date(startTime).toString();
    }

    return str;
  }
@Test
  public void testGetStartTimeStr() {
    JobReport jobReport = mock(JobReport.class);
    when(jobReport.getStartTime()).thenReturn(-1L);

    Job job = mock(Job.class);
    when(job.getReport()).thenReturn(jobReport);
    when(job.getName()).thenReturn("TestJobInfo");
    when(job.getState()).thenReturn(JobState.SUCCEEDED);

    JobId  jobId = MRBuilderUtils.newJobId(1L, 1, 1);
    when(job.getID()).thenReturn(jobId);

    JobInfo jobInfo = new JobInfo(job);
    Assert.assertEquals(JobInfo.NA, jobInfo.getStartTimeStr());

    Date date = new Date();
    when(jobReport.getStartTime()).thenReturn(date.getTime());

    jobInfo = new JobInfo(job);
    Assert.assertEquals(date.toString(), jobInfo.getStartTimeStr());
  }