xml processing instructions lost by documentToRecord

I am working with documents that contain xml processing instructions. For example:

<?xml version="1.0" encoding="UTF-8" ?> <?jdi action="update" ?> Sampl03

When I pass this document through documentToRecord, I get a record like this:

boundNode
@version=1.0
@encoding=UTF-8
JDI
JobPost
@aspect=internal
@postingId=627
JobPostId=Sampl03

Does anyone know of a way I can preserve the processing instruction?