fn test_struct_embedding_with_interface() {
    mut ll := LinearLayout{}
    mut lv := ListView{}
    ll.add(lv)
    ret := ll.layout()

    println(ret)
    assert ret.count('ListView') == 2
}

interface Container {
mut:
    layout() string
}

interface Layoutable {
    get_pos() (int, int)
mut:
    set_pos(int, int)
}

pub struct LayouterBase {
mut:
    layoutables []Layoutable
}

pub fn (mut lb LayouterBase) add(layoutable Layoutable) {
    lb.layoutables << layoutable
}

pub fn (lb LayouterBase) get_pos() (int, int) {
    return 0, 0
}

pub fn (mut lb LayouterBase) set_pos(x int, y int) {}

pub struct LinearLayout {
    LayouterBase
}

pub fn (mut ll LinearLayout) layout() string {
    mut output := ''
    for mut l in ll.layoutables {
        dump(l.type_name())
        output += '${l.type_name()}\n'
        if mut l is Container {
            dump(l.type_name())
            output += '${l.type_name()}\n'
        }
    }
    return output
}

pub struct ListView {
    LayouterBase
}

pub fn (mut lv ListView) layout() string {
    return ''
}