Paging Library 3 and prefetchDistance usage

Question

I am using androidx.paging:paging-*:3.0.0-alpha13

I have such configs for pagination

        PagingConfig(
        pageSize = LOAD_SIZE,
        enablePlaceholders = false,
        initialLoadSize = LOAD_SIZE,
        prefetchDistance = 2 )

I need to load just 'one page' during start (I know that this is not too good practice, but this is required for my case) Despite prefetchDistance = 2 I can see that PageKeyedRemoteMediator loads two pages. Why does it loads second page if prefetch size is too small and visible items at screen just 2-3 and how to make him to load just one page at start