why doesnt underscore wrap work

gistfile1.coffee

  Backbone.sync = (method, entity, options = {}) ->
    
    ## THIS WORKS
    _.each ["beforeSend", "complete", "error"], (fn) ->
      options[fn] or= ->

      orig = options[fn]
      options[fn] = ->
        orig.apply(entity, arguments)
        methods[fn].apply(entity, arguments)

    ## THIS DOES NOT WORK
    _.each ["beforeSend", "complete", "error"], (fn) ->
      options[fn] or= ->

      _.wrap options[fn], (orig) ->
        orig.apply(entity, arguments)
        methods[fn].apply(entity, arguments)