void tagOwner(ParsedDocument owner) {
        verifyThat(ownedBy == null, "already owned by", ownedBy);
        this.ownedBy = owner;
        getStruct().ifPresent(s -> s.tagOwner(owner));
    }
This class holds the extracted information after parsing a
"annotation" block, using simple data structures as far as
possible.  Do not put advanced logic here!
@author arnej27959
config-model/src/main/java/com/yahoo/schema/parser/ParsedAnnotation.java