Null key for a Map not allowed in JSON (use a converting NullKeySerializer?) on withCreateContainerCmdModifier and withNetwork

I was using GenericContainer below and encounter issue

Caused by: org.testcontainers.shaded.com.fasterxml.jackson.databind.JsonMappingException: Null key for a Map not allowed in JSON (use a converting NullKeySerializer?) (through reference chain: org.testcontainers.shaded.com.github.dockerjava.core.command.CreateContainerCmdImpl["NetworkingConfig"]->org.testcontainers.shaded.com.github.dockerjava.core.command.CreateContainerCmdImpl$NetworkingConfig["EndpointsConfig"])

GenericContainer<?> xContainer = new GenericContainer<>("x:latest")
  .withExposedPorts(8080)
  .withCreateContainerCmdModifier(cmd -> cmd.withHostConfig(
    new HostConfig().withPortBindings(new PortBinding(Ports.Binding.bindPort(8080), new ExposedPort(8081)))
  ))
  .withNetwork(network);

further investigation shows that the error exists only when withCreateContainerCmdModifier and withNetwork are used at the same time. If they are used without the other it works. But I need both of them one for mapping to a new port and the other one for networking capabilities. Please advice. Thanks!

GenericContainer のエントリポイント withCreateContainerCmdModifier と withNetwork から始め、次に、示されているイメージ、ポートバインディング、ネットワークの組み合わせを使って reproducer を実行します。生成された NetworkingConfig を追跡し、両方のオプションを使用しても null-map-key JSON エラーが発生しなくなり、各オプションが引き続き単独で機能することを確認します。