public void refreshGUI() {
   if (displayChanges) {
     gui.setContents(instructions, visibleInstructionsLength);
     gui.setCurrentInstruction(nextPC);
   }
 }
 // Sets the gui's contents (if a gui exists)
 private void setGUIContents() {
   if (displayChanges) {
     gui.setContents(instructions, visibleInstructionsLength);
     gui.setCurrentInstruction(nextPC);
   }
 }