public void testGetDurationConverter() {
        DurationConverter c = ConverterManager.getInstance().getDurationConverter(new Long(0L));
        assertEquals(Long.class, c.getSupportedType());
        
        c = ConverterManager.getInstance().getDurationConverter(new Duration(123L));
        assertEquals(ReadableDuration.class, c.getSupportedType());
        
        c = ConverterManager.getInstance().getDurationConverter(new Interval(0L, 1000L));
        assertEquals(ReadableInterval.class, c.getSupportedType());
        
        c = ConverterManager.getInstance().getDurationConverter("");
        assertEquals(String.class, c.getSupportedType());
        
        c = ConverterManager.getInstance().getDurationConverter(null);
        assertEquals(null, c.getSupportedType());
        
        try {
            ConverterManager.getInstance().getDurationConverter(Boolean.TRUE);
            fail();
        } catch (IllegalArgumentException ex) {}
    }