anchor.diff:              options.["y_extended_ticks"] <- true
               options.["target"] <- String.Format("#{0}", guid)
   
  -        member internal this.Template with get() = template and set value = template <- value
  +        member this.HasOption key = options.ContainsKey(key)
  +
  +        member this.xLabel 
  +            with get() : string = this.["x_label"] |> unbox 
  +             and set (value:string) = 
  +                if not <| this.HasOption("x_label") then this.["left"] <- 60                 
  +                this.["x_label"] <- value
  +
  +        member this.yLabel 
  +            with get() : string = this.["y_label"] |> unbox 
  +             and set (value:string) = 
  +                 if not <| this.HasOption("x_label") then this.["bottom"] <- 60
  +                 this.["y_label"] <- value
   
           member this.ToHtml() =
               // FUNC can be used to wrap a javascript function passed to the data_graphic method
  
positive.code:                     .Replace("{GUID}", guid)
                      .Replace("\"FUNC", "").Replace("FUNC\"", "")
  
  
          member this.Item with get(key) = options.[key] and set key (value: obj) = options.[key] <- value
  
      type LineChart() =
          inherit ChartBase()
  
negative.code:             base.["area"] <- false
              base.["x_accessor"] <- "x"
              base.["y_accessor"] <- "y"
              base.["data"] <- Seq.empty<Series>
  
          member this.addSeries (values: (float*float) seq) = 
              let data : Series seq = this.["data"] |> unbox
              this.["data"] <- Seq.append data (seq [values |> Seq.map (fun p -> {x = fst p; y = snd p})])
  
  
      type HistogramChart() =
          inherit ChartBase()
  