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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 _get_image(self):
 """ Get a PIL Image instance of this file. The image is cached to avoid the file needing to be read again if the function is called again. """

        if not hasattr(self, '_image_cache'):
            from easy_thumbnails.source_generators import pil_image
            self.image = pil_image(self)
        return self._image_cache