notifyItemRangeInserted
Notify any registered observers that the currently reflected itemCount items starting at positionStart have been newly inserted. The items previously located at positionStart and beyond can now be found starting at position positionStart + itemCount.
This is a structural change event. Representations of other existing items in the data set are still considered up to date and will not be rebound, though their positions may be altered.
Parameters
positionStart
Position of the first item that was inserted
itemCount
Number of items inserted