   # @param position [Integer] start position for the delta, default: 0
   #
   # @return [Integer] the position of the cursor after parsing the delta
-  deltaHelper : (delta, position = 0) ->
+  deltaHelper= (delta, position = 0) =>
     if delta?
       selections = (@_get "selections")
       delta_unselections = []

        return position + retain
      throw new Error "This part of code must not be reached!"

  insertHelper : (position, content) ->
    as_array =
      if typeof content == "string"
        content.split("")

    if as_array?
      @_get("characters").insertContents position, as_array

  deleteHelper= (position, length = 1) =>
    console.log "deleteHelper"
    (@_get "characters").delete position, length

