Edited Conference Proceedings, Editor names in DataCite XML

[photomedia]

What happens when an item to mint a DOI for is an edited conference proceedings?
More generally, what happens if an item only has an <editor> listed, but not <creators>?
DataCite fails to mint a DOI, because the <creators> field is required, so that's an issue that I'm not sure how to deal with.
More specifically for this plugin, though, I believe that right now, as is, the code doesn't export the <editor> fields at all?
I think that <creators> and <contributors> make it to the export, but <editor> names don't make it out as <contributors> of type "editor"?