CurlRequest result = request.param("key", null);

        assertSame(request, result); // Should not add null parameters
    }

    @Test
    public void testHeaderMethod() {
        CurlRequest request = new CurlRequest(Method.GET, "https://example.com");

        CurlRequest result = request.header("Content-Type", "application/json").header("Accept", "application/json");