Add a range of existing entries from the destination cache.
The entries are placed at the end of the entry list. If any of the entries causes the list to now be incorrectly sorted a final sorting phase will be automatically enabled within {@link #finish()}.
This method copies from the destination cache, which has not yet been updated with this editor's new table. So all offsets into the destination cache are not affected by any updates that may be currently taking place in this editor.
The internal entry table is automatically expanded if there is insufficient space for the new additions.
@param pos first entry to copy from the destination cache.
@param cnt number of entries to copy.