anchor.diff:                      | ty when ty = typeof<System.Enum> -> data |> Seq.map (fun x -> x.ToString())
                       // array type to string
                       | ty when ty.IsArray ->
  -                        data |> Seq.map (toPrettyString separator)
  +                        let stringFunc = 
  +                            let fstRecord = data |> Seq.head
  +                            [|formatFunctionsFst separator fstRecord; formatFunctionsRest separator fstRecord|]
  +                        data
  +                        |> Seq.mapi (fun i value ->
  +                                        if i = 0 then
  +                                            stringFunc.[0] value
  +                                        else
  +                                            stringFunc.[1] value
  +                                    )
                       | ty when ty = typeof<System.Enum> -> data |> Seq.map (fun x -> x.ToString())
                       // union type
                       | ty when FSharpType.IsUnion ty -> data |> Seq.map (fun x -> sprintf "%A" x)
  
positive.code:                     sb.Clear() |> ignore
                      res
  
              Seq.toCSVwith separator header data funcPrecHead funcPrec
negative.code:                         | ty when ty = typeof<System.Enum> -> dataType.Name
                          // array type to string
                          | ty when ty.IsArray ->
                              data |> Seq.map (fun x -> formatFunctionHeader separator (box x) dataType.Name) |> String.concat separator
                          | ty when ty = typeof<System.Enum> -> dataType.Name
                          // union type
                          | ty when FSharpType.IsUnion ty -> dataType.Name
  