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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 fill(self, background_shape, img):
 """ Return a proper background image of background_shape, given img. Args: background_shape (tuple):
 a shape (h, w) img: an image Returns: a background image """

        background_shape = tuple(background_shape)
        return self._fill(background_shape, img)