Add background

[seddikKy]

hello, I want to thank you for sharing the source code, your ExpandableRecyclerView works perfectly, thank you for the effort made.
on the other hand I have a question about the backround, I try to add a drawable border to my childitem but it did not work for me.
could you give me advice so that I can adapt your recyclerview to my needs and thank you in advance.
waiting for a response from you, please accept my most distinguished greetings