code: private OkHttpConnector connector(GitHubServerConfig config) {
          OkHttpClient client = new OkHttpClient().setProxy(getProxy(defaultIfBlank(config.getApiUrl(), GITHUB_URL)));
  
          if (config.getClientCacheSize() > 0) {
              Cache cache = toCacheDir().apply(config);
              client.setCache(cache);
          }
  
          return new OkHttpConnector(new OkUrlFactory(client));
      }
docs: okHttp connector to be used as backend for GitHub client.
  Uses proxy of jenkins
  If cache size > 0, uses cache
  
  @return connector to be used as backend for client