anchor.diff:          match m
               |> value.TryGetProperty with
           | Some x -> x |> f
  -        | None -> Error (JsonError.MissingProperty m)
  +        | None -> Error (JsonError.MissingProperty (m, JsonValue))
   
       member this.Bind(m: string option, f) = 
           m |> Option.bind value.TryGetProperty |> f
  
positive.code:         |> jsonValue.TryGetProperty
          |> Option.bind conversion with
      | Some x -> Ok x
      | None -> Error (JsonError.MissingProperty name)
  
  let Optional (name,conversion) (jsonValue: JsonValue) =
      name
  
negative.code: 
  [<RequireQualifiedAccess>]
  type JsonError =
      | MissingProperty of PropertyName: string * Record: JsonValue
      | InconsistentArray of WrongValues: JsonValue []
  
  let AsString jsonValue = JsonConversions.AsString false culture jsonValue
  