@Override
        public void onSubscribe(Subscription s) {
            ctx.whenRequestCancelling().thenAccept(cause -> {
                if (!onErrorCalled) {
                    s.cancel();
                }
            });
            s.request(Integer.MAX_VALUE);
        }
An abstract {@link Subscriber} implementation which collects objects published by a {@link Publisher}.
core/src/main/java/com/linecorp/armeria/internal/common/util/ObjectCollectingUtil.java