assertEquals("others", fileTypeHelper.get("non/existent"));
    }

    public void test_get_withNullMimetype() {
        assertEquals("others", fileTypeHelper.get(null));
    }

    public void test_get_withEmptyMimetype() {
        assertEquals("others", fileTypeHelper.get(""));
        assertEquals("others", fileTypeHelper.get(" "));
    }

    public void test_get_withBlankFiletype() {