anchor.diff:          |> getDescendants "PropertyGroup"
           |> Seq.fold handleElement defaultProperties
           |> Map.tryFind propertyName
  +
  +    member this.GetProperty propertyName =
  +        this.GetPropertyWithDefaults propertyName Map.empty<string, string>
   
       member this.Name = FileInfo(this.FileName).Name
   
  
positive.code: 
              if !isPaketNode = paketOnes then yield node]
  
      member this.GetProperty propertyName defaultProperties =
          let rec handleElement (data : Map<string, string>) (node : XmlNode) =
              let processPlaceholders (data : Map<string, string>) text =
                  let getPlaceholderValue (name:string) =
  
negative.code:     member this.GetOutputDirectory buildConfiguration =
          let startingData = Map.empty<string,string>.Add("Configuration", buildConfiguration)
  
          this.GetPropertyWithDefaults "OutputPath" startingData
          |> function
              | None -> failwithf "Unable to find %s output path node in file %s" buildConfiguration this.FileName
              | Some s -> s.TrimEnd [|'\\'|] |> normalizePath
  