My code:

public String getTemplate(TestType fileType) {
    Util util = new Util();
    try {
        return util.addPrefix(util.getTemplate(fileType));
    } catch (IOException e) {
        logger.warn(e.getMessage());
        throw new MyException(...);
    } catch (SyntaxException e) {
        logger.warn(e.getMessage());
        throw new MyException(...);
    }
}

Test class:

TestType testType = TestType.main;
CSVUtil csvUtil = spy(new CSVUtil()); //or CSVUtil csvUtil = mock(CSVUtil.class);
when(csvUtil.getTemplate(testType)).thenThrow(new SyntaxException(...)); //or IOException

String out = runService.getTemplate(testType);

But it doesn’t work. Since this method creates a new class.
Is it possible to mock the creation of a new inner class without using PowerMock?