public static final String ERROR_AUTH = "auth_error";

    /** Error code for service unavailable (HTTP 502/503). */
    public static final String ERROR_SERVICE_UNAVAILABLE = "service_unavailable";

    /** Error code for request timeout. */
    public static final String ERROR_TIMEOUT = "timeout";

    /** Error code for context length exceeded. */

    @Test
    public void test_errorCodeConstants() {
        assertEquals("rate_limit", LlmException.ERROR_RATE_LIMIT);
        assertEquals("auth_error", LlmException.ERROR_AUTH);
        assertEquals("service_unavailable", LlmException.ERROR_SERVICE_UNAVAILABLE);
        assertEquals("unknown", LlmException.ERROR_UNKNOWN);
    }

    @Test
    public void test_getErrorCodeWithServiceUnavailable() {