}

    /**
     * Test multiple close() calls (idempotency)
     */
    @Test
    @DisplayName("Test close() method is idempotent")
    public void testCloseIdempotent() {
        NtlmPasswordAuthenticator auth = new NtlmPasswordAuthenticator("user", "IdempotentPass123!");

        assertFalse(auth.isClosed());

        // Close multiple times
        auth.close();