class RestTemplateConfig {

    @Bean
    public RestTemplate restTemplate(ClientHttpRequestFactory factory) {<FILL_FUNCTION_BODY>}

    @Bean
    public ClientHttpRequestFactory simpleClientHttpRequestFactory() {
        OkHttpClient client = new OkHttpClient.Builder()
                .connectTimeout(15, TimeUnit.SECONDS)
                .readTimeout(20, TimeUnit.SECONDS)
                .writeTimeout(20, TimeUnit.SECONDS)
                .build();
        return new OkHttp3ClientHttpRequestFactory(client);
    }

}

        RestTemplate restTemplate = new RestTemplate(factory);
        restTemplate.setInterceptors(Collections.singletonList(new HeaderRequestInterceptor()));
        return restTemplate;
    
<no_super_class>