anchor.diff:          itype.Fields.Value
           |> Array.map (fun field ->
               if field.Args.Length = 0
  -            then (genProperty ctx itype field) :> MemberInfo
  +            then (genProperty ctx field) :> MemberInfo
               else upcast genMethod ctx itype field)
           |> Array.toList
           |> t.AddMembers
  
positive.code:         itype.Fields.Value
          |> Seq.choose (fun field ->
              if field.Args.Length = 0
              then (genProperty ctx itype field) :> MemberInfo |> Some
              else None //TODO: upcast genMethod ctx itype field
          )
          |> Seq.toList
  
negative.code:         itype.Fields.Value
          |> Array.map (fun field ->
              if field.Args.Length = 0
              then (genProperty ctx field) :> MemberInfo
              else upcast genMethod ctx itype field)
          |> Array.toList
          |> t.AddMembers
  