verify(tree, times(1)).release(); // release called in finally exactly once
    }

    @Test
    @DisplayName("remove() throws UnsupportedOperationException with 'remove' message")
    void removeUnsupported() throws Exception {
        // Arrange
        stubAcquireReturnsSelf();
        TestIterator it = TestIterator.create(tree, parent, "*", null, 0, entry("a"), List.of(new FileEntry[][] { new FileEntry[] {} }));