EpoxyVisibilityItem(adapterPosition: Int? = null)
This class represent an item in a android.view.ViewGroup and it is being reused with multiple model via the update method. There is 1:1 relationship between an EpoxyVisibilityItem and a child within the android.view.ViewGroup.
It contains the logic to compute the visibility state of an item. It will also invoke the visibility callbacks on com.airbnb.epoxy.EpoxyViewHolder
This class should remain non-public and is intended to be used by EpoxyVisibilityTracker only.