type T5 interface {
	T6
}

type T6 interface {
	m() T7
}
type T7 interface {
	T5
}

// Actual test case from issue 7158.

func wrapNode() Node {
	return wrapElement()
}

func wrapElement() Element {
	return nil
}

type EventTarget interface {
	AddEventListener(Event)
}

type Node interface {
	EventTarget
}

type Element interface {
	Node
}