[RefCounted] using class nsIURI from "nsIURI.h";

union Union {
    nullable PNullable;
    nullable PNullable[];
    nullable PNullable?;
    nullable nsIURI;
    nullable nsIURI[];
    nullable nsIURI?;
};

protocol PNullable {
child:
    async Msg(nullable PNullable n);
    async Msg2(nullable PNullable[] N);
    async Msg3(nullable PNullable? n);
    async Msg4(nullable nsIURI u);
    async Msg5(nullable nsIURI[] u);
    async Msg6(nullable nsIURI? u);
    async Msg7(Union u);
};