gistfile1.txt

Without:
this.actionManager.registerAction(Input.Keys.F1,new Command() {
            @Override
            public void execute() {
                System.out.println(isMenuShown);
            }
        });
        
        
With lambdas:
        
this.actionManager.registerAction(Input.Keys.F1, () -> System.out.println(isMenuShown));     

With parameters & body

        this.actionManager.registerAction(Input.Keys.F1, (foo, bar) -> {
            System.out.println(foo);
            System.out.println(bar);
        });