Add negative testing example
Add negative testing example

mingtang1079/AnDevCon-RxPatterns,pjq/AnDevCon-RxPatterns,yangpeiyong/AnDevCon-RxPatterns,colintheshots/AnDevCon-RxPatterns,hgl888/AnDevCon-RxPatterns,Saiseizuki/AnDevCon-RxPatterns,MaTriXy/AnDevCon-RxPatterns