verify(handle, times(1)).release();
        verifyNoMoreInteractions(handle);
    }

    @Test
    @DisplayName("ensureDFSResolved(): no exception when underlying call succeeds")
    void ensureDFSResolved_success() throws Exception {
        // Arrange: default mock does nothing

        // Act: call method under test
        handle.ensureDFSResolved();

        // Assert: interaction happened and did not throw