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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 _deprecation_notice(cls):
 """Warn about deprecation of this class."""

        _deprecation_msg = (
            '{name} {type} is deprecated. '
            'It will be removed in the next version. '
            'Use saml2.cryptography.symmetric instead.'
        ).format(name=cls.__name__, type=type(cls).__name__)
        _warnings.warn(_deprecation_msg, DeprecationWarning)