How to use

InitializerState$ExternalizerImpl

in

org.keycloak.models.sessions.infinispan.initializer

@Override
public InitializerState readObject(ObjectInput input) throws IOException, ClassNotFoundException {
  switch (input.readByte()) {
    case VERSION_1:
      return readObjectVersion1(input);
    default:
      throw new IOException("Unknown version");
  }
}