if node has already a doi, no new request will be sent
if node has already a doi, no new request will be sent

edoweb/regal-api,jschnasse/regal-api,jschnasse/regal-api,edoweb/regal-api,edoweb/regal-api,edoweb/regal-api,jschnasse/regal-api,jschnasse/regal-api