Minor Description
Scenario: getXMLStreamReader is called on an OMElement that has an OMSourcedElement as one of its descendents.
Result: After the XMLStreamReader has been consumed, the OMSourcedElement is expanded, even if it is backed by a data source that supports non destructive reads.
When encountering an OMSourcedElement, StAXOMWrapper should insert the events from the XMLStreamReader produced by the OMDataSource instead of generating the events by traversing the OMSourcedElement (which results in its expansion). This is currently not implemented.