When HashMap of last node becomes empty how does it return to the last stage?

[Vikas-G-141583313319037 (VIKAS GOGIA)]

private void display(Node n, String s){

	if(n.isTerminal){
		System.out.println(s.substring(1)+ n.data);
	}
	
	Set<Map.Entry<Character , Node>> set = n.children.entrySet();
	for(Map.Entry<Character , Node> entry : set){
		
		this.display(entry.getValue(), s + n.data);
	}
}