$().ready ->
  window.App = {} # instances

  ### Models  ###
  class window.Stop             extends Backbone.RelationalModel
    url: -> @get('url')
    relations: [{
      type: Backbone.HasOne
      key: 'direction'
      relatedModel: 'Direction'
      collectionType: 'DirectionList'
      reverseRelation: {
        key: 'stops'
      }
    }]

  class window.Direction        extends Backbone.RelationalModel
    url: -> @get('url')
    relations: [{
      type: Backbone.HasOne
      key: 'route'
      relatedModel: 'Route'
      collectionType: 'RouteList'
      reverseRelation: {
        key: 'directions'
      }
    }, {
      type: Backbone.HasMany
      key: 'stops'
      relatedModel: 'Stop'
      collectionType: 'StopList'
      reverseRelation: {
        key: 'direction'
      }
    }]

  class window.Route            extends Backbone.RelationalModel
    url: -> @get('url')
    relations: [{
      type: Backbone.HasOne
      key: 'agency'
      relatedModel: 'Agency'
      collectionType: 'AgencyList'
      reverseRelation: {
        key: 'routes'
      }
    }, {
      type: Backbone.HasMany
      key: 'directions'
      relatedModel: Direction
      collectionType: 'DirectionList'
      reverseRelation: {
        key: 'route'
      }
    }]

  class window.Agency           extends Backbone.RelationalModel
    url: -> @get('url')
    relations: [{
      type: Backbone.HasMany
      key: 'routes'
      relatedModel: Route
      collectionType: 'RouteList'
      reverseRelation: {
        key: 'agency'
      }
    }]

  class window.StopList         extends Backbone.Collection
    model: Stop
    url: -> "#{@get('direction').url()}/stops"

  class window.DirectionList    extends Backbone.Collection
    model: Direction
    url: -> "#{@get('route').url()}/directions"

  class window.RouteList        extends Backbone.Collection
    model: Route
    url: -> "#{@get('agency').url()}/routes"

  class window.AgencyList       extends Backbone.Collection
    model: Agency
    url: -> "/agencies"

  App.agencies = new AgencyList

  # setup
  App.agencies.fetch()
  a1 = App.agencies.first()
  a1.fetchRelated()
  rs = a.get('routes')

  # the issue
  a2 = rs.get('agency')
  # a2 should equal a1, but instead, a2 is undefined
  # help?