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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 identifier(self, mask: str = '##-##/##') -> str: """Generate a random identifier by mask. With this method you can generate any identifiers that you need. Simply select the mask that you need. :param mask: The mask. Here ``@`` is a placeholder for characters and ``#`` is placeholder for digits. :return: An identifier. :Example: 07-97/04 """

        return self.random.custom_code(mask=mask)