Problem with expand/collapse

[ghost]

Hi,
I followed every instruction about creating expandable items but the problem is that the code is executed there is no error at all but items of recyclerview are not expanded.
I checked logs it says that : "item expanded" but I don't see any change in the application.
Should I have some special attribute in xml file?!

[AllenCoder]

https://github.com/CymChad/BaseRecyclerViewAdapterHelper/wiki/Expandable-Item