@Override
    public int getViewTypeCount() {
        return mDelegate.getViewTypeCount() + sNumViewTypes;
    }
Get the data item associated with the specified position in the data set.
<p>
Since this wrapper inserts fake entries to fill out items grouped by
header and also spaces to insert headers into some positions will return
null.
</p>

@param position Position of the item whose data we want within the
           adapter's data set.
@return The data at the specified position.
Library/src/com/tonicartos/widget/stickygridheaders/StickyGridHeadersBaseAdapterWrapper.java