public virtual OnForeignKeyAddedNode VisitOnForeignKeyAdded(OnForeignKeyAddedNode node) => node;
 public override OnForeignKeyAddedNode VisitOnForeignKeyAdded(OnForeignKeyAddedNode node)
 {
     Dispatcher._immediateConventionScope.OnForeignKeyAdded(node.RelationshipBuilder);
     return(null);
 }