private void verifyUserMetadataHeadersAbsent(HttpResponse response) {
    for (Map.Entry<String, String> header : response.headers()) {
      String key = header.getKey();
      if (key.startsWith(RestUtils.Headers.USER_META_DATA_HEADER_PREFIX)) {
        fail("Key " + key + " should not be present in headers");
      }
    }
  }
Verifies User metadata headers from output, to that sent in during input
@param response the {@link HttpResponse} which contains the headers of the response.
ambry-frontend/src/integration-test/java/com/github/ambry/frontend/FrontendQuotaIntegrationTest.java