Even if topic category is mandatory from an ISO point of view, some records may not defined it.
Make the mapping more robust on this point and avoid
java.lang.NullPointerException: null
at org.fao.geonet.index.converter.DcatConverter.convert(DcatConverter.java:156) ~[classes/:na]
at org.fao.geonet.ogcapi.records.controller.ItemApiController.collectionsCollectionIdItemsRecordIdGetAsJsonLd(ItemApiController.java:291) ~[classes/:na]
Even if topic category is mandatory from an ISO point of view, some records may not defined it.
Make the mapping more robust on this point and avoid