public AtomicLong clientCaCertificateExpiration(String clusterName, String namespace) {
        return getGaugeLong(new CertificateMetricKey(kind, namespace, clusterName, CertificateMetricKey.Type.CLIENT_CA),
                METRICS_CERTIFICATE_EXPIRATION_MS, "Time in milliseconds when the certificate expires",
                Optional.empty(), certificateExpirationMap,
                Tag.of("cluster", clusterName),
                Tag.of("type", CertificateMetricKey.Type.CLIENT_CA.getDisplayName()),
                Tag.of("resource-namespace", namespace));
    }
@Test
    @DisplayName("Should return correct expiration time for client CA certificate")
    void shouldReturnCorrectExpirationTimeForClientCaCertificate() {
        AtomicLong expirationTime = metricsHolder.clientCaCertificateExpiration("TestCluster", "TestNamespace");

        assertEquals(1000L, expirationTime.get(), "Expiration time should match the initial value");
    }