protected override Expression <Func <MsBuildPropertyGroupListAssociation, bool> > FindExisting(MsBuildPropertyGroupListAssociation record)
 => existing
 => existing.MsBuildPropertyGroupId == record.MsBuildPropertyGroupId &&
 existing.MsBuildPropertyGroupListId == record.MsBuildPropertyGroupListId;
        protected override IEnumerable <object> EnumerateReferences(MsBuildPropertyGroupListAssociation record)
        {
            yield return(record.MsBuildPropertyGroup);

            yield return(record.MsBuildPropertyGroupList);
        }