Select spacing between buttons

Select spacing between buttons

I have a collection of buttons:
VBox menuButtons = new VBox();
menuButtons.getChildren().addAll(addButton, editButton, exitButton);
I want to add some spacing between this buttons, whitout using a CSS
sheet. I think there should be a way for this.
setPadding(); is for the Buttons in the Box. setMargin(); should be for
the Box itself. But I didn't found a way for the spacing between the
buttons.
I'm glad for any ideas. :)