sync pyglet update

libs/pyglet/sprite.py

@@ -400,6 +400,7 @@ class Sprite(event.EventDispatcher):
                                        self._group.blend_dest,
                                        self._group.program,
                                        group)
+        if self._batch is not None:
             self._batch.migrate(self._vertex_list, GL_TRIANGLES, self._group, self._batch)
 
     @property

libs/pyglet/window/__init__.py

@@ -1799,7 +1799,9 @@ class FPSDisplay:
     usage is to create an `FPSDisplay` for each window, and draw the display
     at the end of the windows' :py:meth:`~pyglet.window.Window.on_draw` event handler::
 
-        window = pyglet.window.Window()
+        from pyglet.window import Window, FPSDisplay
+
+        window = Window()
         fps_display = FPSDisplay(window)
 
         @window.event