The unit tests highlighted that without passing an frameworkcode to the
MarcSubfieldStructures->find call we throw errors as we can't identify
the correct subfield structure rules to apply.
This patch adds the default frameworkcode, empty string, to the lookup.
Signed-off-by: Martin Renvoize <martin.renvoize@ptfs-europe.com>
Signed-off-by: Katrin Fischer <katrin.fischer@bsz-bw.de>
914022d30d