code: public Item getItem(int position) {
          //if we are out of range just return null
          if (position < 0 || position >= mGlobalSize) {
              return null;
          }
          //now get the adapter which is responsible for the given position
          int index = floorIndex(mAdapterSizes, position);
          return mAdapterSizes.valueAt(index).getAdapterItem(position - mAdapterSizes.keyAt(index));
      }
docs: gets the IItem by a position, from all registered adapters
  
  @param position the global position
  @return the found IItem or null