Configuring same network for multiple generic containers does not work

I am trying to create multiple containers using testcontainers lib which are sharing the same Network. What do I have right now is the following:

network = Network.newNetwork();

container1 = new GenericContainer<>().withNetwork(network)...
container2 = new GenericContainer<>().withNetwork(network)...

// variables' type and other builder details omitted for brevity

The container startup works fine, but when I do a docker inspect for each of these containers, I see that only container1 is assigned to the freshly created network. Any reason why this is happening?

It turns out that those "details omitted for brevity" did the difference. There was such a coincidence that the first container I tried to start had the following configuration:

.withCreateContainerCmdModifier(cmd -> cmd.getHostConfig().withPortBindings(
        new PortBinding(Ports.Binding.bindPort(8443), new ExposedPort(8443)),
        new PortBinding(Ports.Binding.bindPort(8080), new ExposedPort(8080))))
 

and the second container:

.withCreateContainerCmdModifier(
        createContainerCmd -> createContainerCmd.withHostConfig(new HostConfig().withPortBindings(
                new PortBinding(Ports.Binding.bindPort(9042), new ExposedPort(9042)),
                new PortBinding(Ports.Binding.bindPort(9142), new ExposedPort(9142)))))

Note the important difference between these two - getHostConfig() and withHostConfig(new HostConfig()). The second one, of course, overrides any network configuration set initially.

Fixed by using getHostConfig() for both containers.