         return position + retain
       throw new Error "This part of code must not be reached!"
 
-  insertHelper : (position, content) ->
+  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


  # @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) =>
    if delta?
      selections = (@_get "selections")
      delta_unselections = []
