Parent property isn't exposed for LastRevision access to WI

[yan95g]

Steps to Reproduce:

1. having link to last revision of workitem
   var Last = self.LastRevision
2. try to get access to Parent in order to get linked WI
   var parent = Last.Parent

Rule example:

<rule name="TakeLastParent" appliesTo="Bug,Product Backlog Item">
    <![CDATA[
      if (!self.HasParent())
	   {var sum = 0.0;
		var parentFeature = self.LastRevision.Parent;
	    sum = parentFeature.Children.Where(c => ((string)c["System.WorkItemType"])=="Bug" || ((string)c["System.WorkItemType"])=="Product Backlog Item").Sum(c => c.GetField<double>("Microsoft.VSTS.Scheduling.Effort",0.0));
        parentFeature.Fields["Microsoft.VSTS.Scheduling.Effort"].Value = sum;
	   }
	]]>		
</rule>

Expected Result:
code is compiled and provide access to Parent WI if that exists including access to fields and values
Actual Result:
following error is thrown by console app:

[Error] 04.774 Error CS1061 in script 'TakeLastParent' at line 5, column 42: 'Aggregator.Core.Interfaces.IRevision' does not contain a definition for 'Parent' and no extension method 'Parent' accepting a first argument of type 'Aggregator.Core.Interfaces.IRevision' could be found (are you missing a using directive or an assembly reference?)

Environment:
TFS 2017 U2 On Premise - TFS Aggregator Server Plugin 2.3 RC1

[jessehouwing]

OHh I remember... In the object model that link collection is of yet another type than the standard link collection, which is why I had decided not to add it when we added link support and revision support.