#vulnerable code 
                             @Test
	public void testMinusWorkdaysFromFriday() {

		Calendar startDate = Calendar.getInstance();
		// adjust to FRIDAY
		startDate.set(Calendar.DAY_OF_WEEK, Calendar.FRIDAY);
		System.out.println("Startdate=" + startDate.getTime());

		// adjust -3 Workdays -> THUSEDAY
		Assert.assertEquals(Calendar.THURSDAY,
				WorkflowSchedulerService.addWorkDays(startDate, -1).get(Calendar.DAY_OF_WEEK));
		Assert.assertEquals(Calendar.WEDNESDAY,
				WorkflowSchedulerService.addWorkDays(startDate, -2).get(Calendar.DAY_OF_WEEK));
		Assert.assertEquals(Calendar.MONDAY,
				WorkflowSchedulerService.addWorkDays(startDate, -4).get(Calendar.DAY_OF_WEEK));
		// friday - 5
		Assert.assertEquals(Calendar.FRIDAY,
				WorkflowSchedulerService.addWorkDays(startDate, -5).get(Calendar.DAY_OF_WEEK));
		Assert.assertEquals(Calendar.MONDAY,
				WorkflowSchedulerService.addWorkDays(startDate, -9).get(Calendar.DAY_OF_WEEK));
		Assert.assertEquals(Calendar.FRIDAY,
				WorkflowSchedulerService.addWorkDays(startDate, -10).get(Calendar.DAY_OF_WEEK));

	} 
                            #location 15 
                            #vulnerability type NULL_DEREFERENCE
#fixed code
                             @Test
	public void testMinusWorkdaysFromFriday() {

		Calendar startDate = Calendar.getInstance();
		// adjust to FRIDAY
		startDate.set(Calendar.DAY_OF_WEEK, Calendar.FRIDAY);
		System.out.println("Startdate=" + startDate.getTime());

		// adjust -3 Workdays -> THUSEDAY
		Assert.assertEquals(Calendar.THURSDAY,
				workflowSchedulerService.addWorkDays(startDate, -1).get(Calendar.DAY_OF_WEEK));
		Assert.assertEquals(Calendar.WEDNESDAY,
				workflowSchedulerService.addWorkDays(startDate, -2).get(Calendar.DAY_OF_WEEK));
		Assert.assertEquals(Calendar.MONDAY,
				workflowSchedulerService.addWorkDays(startDate, -4).get(Calendar.DAY_OF_WEEK));
		// friday - 5
		Assert.assertEquals(Calendar.FRIDAY,
				workflowSchedulerService.addWorkDays(startDate, -5).get(Calendar.DAY_OF_WEEK));
		Assert.assertEquals(Calendar.MONDAY,
				workflowSchedulerService.addWorkDays(startDate, -9).get(Calendar.DAY_OF_WEEK));
		Assert.assertEquals(Calendar.FRIDAY,
				workflowSchedulerService.addWorkDays(startDate, -10).get(Calendar.DAY_OF_WEEK));

	}