if (configuration.getJsonHandler() != null) {
jsonHandler = configuration.getJsonHandler();
}
if (jsonHandler == null) {
jsonHandler = new JsonHandler();
}
if (configuration.getBatchedMethodsExecutionPolicy() == BatchedMethodsExecutionPolicy.CONCURRENT
&& configuration.getBatchedMethodsExecutorService() == null) {
configuration.setBatchedMethodsExecutorService(Executors.newFixedThreadPool(5));