private void appendRequestId(String requestId){
  if (isNotValidRequestId(requestId)) {
    return;
  }
  RequestLog.addIdPrefix(requestId);
}

private void appendRequestId ( String requestId ) { if ( isNotValidRequestId ( requestId ) ) { return ; } RequestLog . addIdPrefix ( requestId ) ; }
add a request id to pass to druid . only added if x - request - id follows the format specified at : https : / / devcenter . heroku . com / articles / http - request - id
