} catch (CurlException e) {
            assertTrue(e.getMessage().contains("Failed to"));
            assertNotNull(e.getCause());
        }
    }

    @Test
    public void test_ConnectException_ViaExceptionListener() throws Exception {
        // ## Arrange ##
        CurlRequest req = new OpenOverrideCurlRequest(Curl.Method.GET, "http://dummy", u -> {
            throw new IOException("Simulated connection failure");