v/vlib/v/tests/nested_map_index_test.v

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'
}