@Override
    public void toData(DataOutput out,
        SerializationContext context) throws IOException {
      super.toData(out, context);
      DataSerializer.writeObject(this.context, out);
    }
Creates a new {@code RegistrationContextMessage} that broadcasts that the given
{@code Instantiator} was registered.
geode-core/src/main/java/org/apache/geode/internal/InternalInstantiator.java