}
    
    @Test
    public void testCopyUnknownFieldsHandler() throws MetadataException {
        Directory d = mock(Directory.class);
        Tag t1 = mock(Tag.class);
        when(t1.getTagName()).thenReturn("Image Description");
        when(t1.getDescription()).thenReturn("t1");
        Tag t2 = mock(Tag.class);
        when(t2.getTagName()).thenReturn(Metadata.KEYWORDS);
        when(t2.getDescription()).thenReturn("known");
        Tag t3 = mock(Tag.class);
        when(t3.getTagName()).thenReturn(TikaCoreProperties.DESCRIPTION.getName());
        when(t3.getDescription()).thenReturn("known");
        List<Tag> tags = Arrays.asList(t1, t2, t3);
        when(d.getTags()).thenReturn(tags);
        Metadata metadata = new Metadata();
        new ImageMetadataExtractor.CopyUnknownFieldsHandler().handle(d, metadata);
        assertEquals("t1", metadata.get("Image Description"));