Defines which metadatum is mapped on which metadatum. Note that while the key must be unique it
only matters here for postprocessing of the value. The mapped MetadatumContributor has full control over
what metadatafield is generated.
yyyy-MMM-dd
yyyy-MMM
yyyy-MM-dd
yyyy
Defines how an org.dspace.content.Item is mapped to a query in scopus. Please note that exactly one of
these must be present. If multiple are present the result is undefined.