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Solve the following problem using Python, implementing the functions described below, one line at a time
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Description:
 def _game_image_from_screen(self, game_type):
 """Return the image of the given game type from the screen. Return None if no game is found. """

        # screen
        screen_img = self._screen_shot()
        # game image
        game_rect = self._game_finders[game_type].locate_in(screen_img)
        if game_rect is None:
            return
        t, l, b, r = game_rect
        game_img = screen_img[t:b, l:r]
        return game_img