How to show 2 images in one opencv windows as pip?

hi guys
i searched many times in internet but i couldn’t find any solution for my question
how to show 2 images in one opencv windows as pip???
show a small images in bigger image
(not beside together in horizntal or vertical)
i want it be same this image
or at least show smaller image in a windows on top of bigger image (without border)
thanks

see OpenCV: Basic Operations on Images