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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(self, key, identity='image'):
 """ Deserializing, prefix wrapper for _get_raw """

        value = self._get_raw(add_prefix(key, identity))

        if not value:
            return None

        if identity == 'image':
            return deserialize_image_file(value)

        return deserialize(value)