anchor.diff:  Append all items from the given category to the items picker.
   ###
   append_items_by_category = (category_id) ->
  -  items_by_category[category_id].forEach (item) ->
  +  append_items(items_by_category[category_id])
  +
  +###
  +Add the given items to the items picker.
  +###
  +append_items = (items) ->
  +  items.forEach (item) ->
       $('#items').append create_button(item.name)
   
   ###
  
positive.code:     # We're already displaying all items
      return
    clear_items()
    for category_id of items_by_category
      append_items_by_category category_id
    activate btn
    return
  
  
negative.code: # Include routes helpers
  <% environment.context_class.instance_eval { include Rails.application.routes.url_helpers } %>
  
  all_items = JSON.parse('<%= raw Item.order(:name).select(:name).to_json %>')
  
  items_by_category = JSON.parse(
    '<%= raw Category.order(:name).map { |category|
  