docs: protected synchronized OkHttpClient getOkHttpClient() {
      if (okHttpClient == null) {
        if (isEnableDebug()) {
          HttpLoggingInterceptor logging = new HttpLoggingInterceptor();
          logging.setLevel(HttpLoggingInterceptor.Level.BASIC);
          OkHttpClient.Builder httpClient = new OkHttpClient.Builder();
          httpClient.addInterceptor(logging);
          okHttpClient = httpClient.build();
        } else {
          okHttpClient = new OkHttpClient();
        }
      }
      return okHttpClient;
    }