assertEquals(70, docList.getProcessingTime());

        docList.addProcessingTime(-100);
        assertEquals(-30, docList.getProcessingTime());
    }

    @Test
    public void test_addContentSize_zero() {
        DocList docList = new DocList();

        docList.addContentSize(0);
        assertEquals(0, docList.getContentSize());

        docList.addContentSize(100);