   @return {SketchItem[]/null} return.PromiseValue
     Array of generated items
   ###
-  setup: (sketch, item) ->
-    return Promise.reject(Error("Pure method"))
+  setup: null # pure virtual
 
   ###*
   @template

  Script execution engine (Model)
@extends JSONable
###
class Engine extends JSONable
  null

  #--------------------------------------------------------------------------------

  ###*
  @template
  @static
  @property {string} friendlyName
    Name of engine
  @readonly
  ###
  @classProperty("coreName", get: -> null)
