!7

abstract sclass DynSCPWithInput extends DynSCP {
  InputChooser inputChooser = new(this);
  
  visualize { ret northAndCenter(wrap(inputChooser), super.visualize()); }
  
  abstract void update(S input);

  void update {
    if (inputChooser.update())
      update(inputChooser.input());
  }
}