# Factorize common proxy implementation
private abstract class ProxyQueue[E]
	super Queue[E]
	var seq: Sequence[E]

	redef fun add(e) do seq.add(e)
	redef fun length do return seq.length
	redef fun is_empty do return seq.is_empty
	redef fun iterator do return seq.iterator
	redef fun remove(e) do seq.remove(e)
end