/**
  * Creates a new experiment by loading a model and an experiment runner. Called when NEW button is
  * pressed.
  */
 void createNewExperiment() {
   experimentGUI.loadModel();
   if (model != null) {
     if (expRunnerClass == null) expRunnerClass = ExperimentRunner.class;
     filename = null;
     docNode = null;
     resetModel();
   }
 }