def createAnimation(descriptor, images, states):
     previewWatchFace = WatchFace(descriptor)
     for watchState in states:
         image = PreviewGenerator.createFrame(previewWatchFace, images,
                                              watchState)
         yield image
 def createImage(descriptor, images, state):
     previewWatchFace = WatchFace(descriptor)
     return PreviewGenerator.createFrame(previewWatchFace, images, state)