public List<MetricsKey> getMetricsKeys() {
        return metricsKeys;
    }
@Override
    @Test
    public void testSerialize() throws JsonProcessingException {
        ClientConfigMetricRequest clientMetrics = new ClientConfigMetricRequest();
        clientMetrics.putAllHeader(HEADERS);
        clientMetrics.getMetricsKeys()
                .add(ClientConfigMetricRequest.MetricsKey.build(CACHE_DATA, String.join("+", KEY)));
        clientMetrics.getMetricsKeys()
                .add(ClientConfigMetricRequest.MetricsKey.build(SNAPSHOT_DATA, String.join("+", KEY)));
        final String requestId = injectRequestUuId(clientMetrics);
        String json = mapper.writeValueAsString(clientMetrics);
        assertTrue(json.contains("\"type\":\"" + "cacheData" + "\""));
        assertTrue(json.contains("\"type\":\"" + "snapshotData" + "\""));
        assertTrue(json.contains("\"key\":\"" + String.join("+", KEY) + "\""));
        assertTrue(json.contains("\"module\":\"" + Constants.Config.CONFIG_MODULE));
        assertTrue(json.contains("\"requestId\":\"" + requestId));
    }