       if not @_base
         @_base = require('./base')
       return @_base
-      
+
     url: () ->
       # ### method HasProperties::url
       #model where our API processes this model

           @properties[key]['setter']
          @properties[key]['setter'].call(this, val)
          toremove.push(key)
      for key in toremove
        delete attrs[key]
      if not _.isEmpty(attrs)
        super(attrs, options)


      super(attrs, options)

      #cheap memoization, requirejs doesn't seem to do it
      @_base = false
      @properties = {}
      @property_cache = {}
      if not _.has(attrs, @idAttribute)
