sclass G22_TestScreenPanel is IHasChangeListeners {
  event change;
  settableWithChange S script;
  
  ImageSurface isInput;
  JGazelleVScriptRunner scriptRunner;
  
  start {
    scriptRunner = new JGazelleVScriptRunner(
      liveValue_hasChangeListeners(this, S.class, -> script, x -> script = x));
  }
}