anchor.diff:          | Some func ->
               let inner = ValueTypeSerializer.getInnerTextWriter XmlConfig.Instance.SpecialCharEncoding
               let writer = (fun a (w : TextWriter) x ->
  -                let obj = func.Invoke(x) 
  +                let obj = func.Invoke(x)
                   if obj <> null then inner a w obj)
               if not XmlConfig.Instance.UseAttributes then
                   injectWriteTag writer
  
positive.code:         writeFunc info w value
          w.Write("</"); w.Write(name); w.Write('>')
  
      /// XML tag writer function with an additional namespace attribute
      let writeTagNamespace (ns : string) (name : string) (info : NameInfo) (w : TextWriter) writeFunc (value : obj) =
          w.Write('<'); w.Write(name); w.Write(" xmlns=\""); w.Write(ns); w.Write("\">")
          writeFunc info w value
          w.Write("</"); w.Write(name); w.Write('>')
  
  
negative.code:         match t.GetMethod(writerFuncName, staticFlags, null, [| t |], null) |> Utils.toOption with
          | Some func ->
              let inner = ValueTypeSerializer.getInnerTextWriter XmlConfig.Instance.SpecialCharEncoding
              let writer = (fun a (w : TextWriter) x ->
                  let obj = func.Invoke(null, [| x |])
                  if obj <> null then inner a w obj)
              if not XmlConfig.Instance.UseAttributes then
  