public static PathCache empty() {
        return EMPTY;
    }
@Test
    public void testDisabledCache() {
        PathCache cache = PathCache.empty();
        final Path file = new Path("name", EnumSet.of(Path.Type.file));
        cache.put(file, AttributedList.emptyList());
        assertFalse(cache.containsKey(file));
        assertEquals(0, cache.size());
    }