             next(201, true),
             next(205, false),
             next(209, true),
-            completed(600),
             ])
         
         let res = scheduler.start(1000) {

            next(220, 2),
            next(230, 3),
            next(400, 6),
            completed(600),
            ])
        
        XCTAssertEqual(underlying.subscriptions, [

            next(301, 4),
            next(350, 5),
            next(399, 6),
            completed(500),
            ])
        
        XCTAssertEqual(underlying.subscriptions, [
