public Relation Relation(
Project project,
String leftName,
Domain left,
Cardinality leftCardinality,
String rightName,
Domain right,
Cardinality rightCardinality,
Expression join) {
RelationPK pk = new RelationPK(project.getId(), getNewID());
Relation relation =
new Relation(
pk,
left.getId(),
leftCardinality,
right.getId(),
rightCardinality,
leftName,
rightName,
join);
RelationServiceBaseImpl.getInstance().store(ctx, relation);
return relation;
}