const layout = new VerticalLayout({
 // pattern defines how elements will be positioned
 // This pattern tells us that we have elements of id's `"a"`, `"b"` and `"c"`
 // Where `"a"` height spans over two units whereas `"b"` and `"c"` each height's span over 1 unit
 //
 // You can think of units as proportions:
 //  - This pattern is 4 unit wide (we defined 4 elements in array)
 //  - a is defined two times, this means it will be 2 unit wide (2/4, it will take 50% of the available space)
 //  - b and c are each defined one time, this means they will be 1 unit wide(1/4, they both will take 25% of remaining space)
 pattern: [ "a", "a", "b", "c" ],
 // gapX defines a horizontal gap (margin) between vertical layouts rectangle and elements
 gapX: 0,
 // gapY defines a vertical gap (margin) between every vertical layouts element
 gapY: 0,
 // Size of a VerticalLayout, `tui.rectangle` means we want to occupy the whole Tui's space
 rectangle: tui.rectangle,
});

// To make elements use layout, you need to set their rectangle as VerticalLayout.element(layoutId)
const buttonA = new Button({
  ...properties,
  rectangle: layout.element("a"),
});

const buttonB = new Button({
  ...properties,
  rectangle: layout.element("b"),
});

const buttonC = new Button({
  ...properties,
  rectangle: layout.element("c"),
});