code: public void insert(final int index, final Object... items) {
          if (mAnimateAdditionAdapter == null) {
              throw new IllegalStateException("Adapter should implement Insertable!");
          }
          mAnimateAdditionAdapter.insert(index, items);
      }
docs: Inserts items, starting at given index. Will show an entrance animation for the new items if the newly added items are visible.
  Will also call {@link Insertable#add(int, Object)} of the root {@link android.widget.BaseAdapter}.
  
  @param index the starting index the new items should be inserted at.
  @param items the items to insert.
  
  @throws java.lang.IllegalStateException if the adapter that was set does not implement {@link com.nhaarman.listviewanimations.util.Insertable}.