@@ -0,0 +1,348 @@
+package jetbrains.jetpad.model.event;%0A%0Aimport jetbrains.jetpad.base.Handler;%0A%0Apublic class ValueListeners%3CValueT%3E extends Listeners%3CHandler%3CValueT%3E%3E %7B%0A  public void fire(final ValueT value) %7B%0A    fire(new ListenerCaller%3CHandler%3CValueT%3E%3E() %7B%0A      @Override%0A      public void call(Handler%3CValueT%3E l) %7B%0A        l.handle(value);%0A      %7D%0A    %7D);%0A  %7D%0A%7D%0A

introduce ValueListeners