* Item, Sequence, ItemEnum, AbstractItem
* item, seq
* seq enum
* seq enum
* items
* items
* AbstractNodeWrapper
* cleanup
* hasMoreItems
* enm
* remove abstract item. don't need
* XPSequenceExpression
* atomic seq
* basic atomic seq works.
* cleanup
* XPNodeSetValue -> XPSequenceValue
* -nextValue
* seq with 3 items working
* cleaqnup
* seq extent