@Test
    public void testDGN() throws Exception {
        assertTypeByName("image/vnd.dgn", "testDGN7.dgn");
        assertTypeByName("image/vnd.dgn", "testDGN8.dgn");
        assertTypeByData("image/vnd.dgn; version=7", "testDGN7.dgn");
    }
Note - detecting container formats by mime magic is very very
iffy, as we can't be sure where things will end up.
People really ought to use the container aware detection...
tika-parsers/tika-parsers-standard/tika-parsers-standard-package/src/test/java/org/apache/tika/mime/TestMimeTypes.java