ChildViewHolder with RecyclerView. LazyLoad

[ghost]

Hello.
I want add to my project expandabler recyclerView where Parent is category, Child is item.
Since there are too many children for each parent, I would like to use lazy loading, but I have problem: I dont know how release it.
After the adapter is initially loaded, the scroll handler in recyclerView starts to work, so the lazy load is repeated again and again until it loads all available items, while the linearManager, when called .getLastVisibleItem, outputs the most recent item in the list, although it is not visible.

Can someone suggest an example of implementing a lazy load in case the child element is a recyclerView?