       tile_options =
         x_origin_offset : 0
         y_origin_offset : 0
-      offset_source = new TMSTileSource(tile_options)
+      offset_source = new TMSTileSource.Model(tile_options)
       bounds = offset_source.get_tile_meter_bounds(0, 0, 16)
       expect(bounds).to.include(0)
 

      tile_options =
        url : 'http://c.tile.openstreetmap.org/{Z}/{X}/{Y}.png'

      source = new TMSTileSource(tile_options)

      [xmin, ymin, xmax, ymax, level] = [-90.283741, 29.890626, -89.912952,
                                          30.057766, 11]

    tile_options =
      url : 'http://mt0.google.com/vt/lyrs=m@169000000&hl=en&x={X}&y={Y}&z={Z}&s=Ga'

    source = new WMTSTileSource.Model(tile_options)

    it "should get tiles for extent correctly", ->
      T.expect_mercator_tile_counts(source)
