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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 _replace_old_image(self):
        ''' Override this in subclass if you don't want
            image replacing or want to customize image replacing
        '''
        try:
            old_obj = self.__class__.objects.get(pk=self.pk)
            if old_obj.image.path != self.image.path:
                path = old_obj.image.path
                default_storage.delete(path)
        except self.__class__.DoesNotExist:
            pass