Saxon

The result type is declared as Sequence. There are a number of implementations of Sequence which you can use. If you're happy to accumulate all the results in memory before returning them, then the most convenient is probably to put the nodes in a Java list, and then

return new SequenceExtent(new ListIterator(list))

As for the nodes themselves, they must implement the NodeInfo interface, and there's a wide range of different ways you can get NodeInfo instances - for starters it depends on whether you are selecting existing nodes, wrapping nodes in an external model such as JDOM, or creating nodes from scratch.

Yes, the SequenceExtent was what I was looking for. Thank you for your time!