}
if (collectionName == null) {
throw ctxt.instantiationException(DBRef.class, "DBRef contains no collection name");
}
JacksonDBCollection coll = ((JacksonDBCollectionProvider) jp).getDBCollection();
JacksonDBCollection<T, K> refColl = coll.getReferenceCollection(collectionName, type, keyType);
return new FetchableDBRef<T, K>(id, refColl);
} else {
throw ctxt.instantiationException(DBRef.class, "DBRef can only be deserialised by this deserializer if parser implements " + JacksonDBCollectionProvider.class.getName());
}
}