code: private static OkHttpClient createOkHttpClient(Long timeoutSeconds) {
          OkHttpClient.Builder builder = new OkHttpClient.Builder();
          if (timeoutSeconds != null) {
              builder.connectTimeout(timeoutSeconds, TimeUnit.SECONDS);
              builder.readTimeout(timeoutSeconds, TimeUnit.SECONDS);
              builder.writeTimeout(timeoutSeconds, TimeUnit.SECONDS);
          }
          return builder.build();
      }
docs: Create OkHttpClient client for Web3j.
  
  @param timeoutSeconds, can be null
  @return OkHttpClient.