public abstract void filter(Metadata metadata) throws TikaException;
@Test
    public void testConfigIncludeAndUCFilter() throws Exception {
        TikaConfig config = getConfig("TIKA-3137-include-uc.xml");
        String[] expectedTitles = new String[]{"TITLE1", "TITLE2", "TITLE3"};
        Metadata metadata = new Metadata();
        metadata.add("title", "title1");
        metadata.add("title", "title2");
        metadata.add("title", "title3");
        metadata.set("author", "author");
        metadata.set("content", "content");

        config.getMetadataFilter().filter(metadata);

        assertEquals(2, metadata.size());
        assertArrayEquals(expectedTitles, metadata.getValues("title"));
        assertEquals("AUTHOR", metadata.get("author"));
    }