docs: private void initRestTemplate() {
  
  		boolean isContainsConverter = false;
  		for (HttpMessageConverter<?> httpMessageConverter : this.restTemplate.getMessageConverters()) {
  			if (MappingJacksonRPC2HttpMessageConverter.class.isAssignableFrom(httpMessageConverter.getClass())) {
  				isContainsConverter = true;
  				break;
  			}
  		}
  
  		if (!isContainsConverter) {
  
  			final MappingJacksonRPC2HttpMessageConverter messageConverter = new MappingJacksonRPC2HttpMessageConverter();
  			messageConverter.setObjectMapper(this.getObjectMapper());
  
  			final List<HttpMessageConverter<?>> restMessageConverters = new ArrayList<>();
  			restMessageConverters.addAll(this.restTemplate.getMessageConverters());
  			// Place JSON-RPC converter on the first place!
  			restMessageConverters.add(0, messageConverter);
  
  			this.restTemplate.setMessageConverters(restMessageConverters);
  		}
  
  		// use specific JSON-RPC error handler if it has not been changed to custom 
  		if (restTemplate.getErrorHandler() instanceof org.springframework.web.client.DefaultResponseErrorHandler) {
  			restTemplate.setErrorHandler(JsonRpcResponseErrorHandler.INSTANCE);
  		}
  	}