struct Foo {
mut:
    foo map[int]Bar
}

struct Bar {
mut:
    bar map[int]string
}

fn test_nested_map_index() {
    f := Foo{
        foo: {
            11: Bar{
                bar: {
                    22: 'hello'
                }
            }
        }
    }
    ret := f.foo[11]!.bar[22]!
    println(ret)
    assert ret == 'hello'
}