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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 _execute(self, intf, mechanism, token):
 """ Execute a SASL authentication process. :param intf: SASL interface to use :type intf: :class:`~.sasl.SASLXMPPInterface` :param mechanism: SASL mechanism to use :type mechanism: :class:`aiosasl.SASLMechanism` :param token: The opaque token argument for the mechanism :type token: not :data:`None` :raises aiosasl.AuthenticationFailure: if authentication failed due to bad credentials :raises aiosasl.SASLFailure: on other SASL error conditions (such as protocol violations) :return: true if authentication succeeded, false if the mechanism has to be disabled :rtype: :class:`bool` This executes the SASL authentication process. The more specific exceptions are generated by inspecting the :attr:`aiosasl.SASLFailure.opaque_error` on exceptinos raised from the :class:`~.sasl.SASLXMPPInterface`. Other :class:`aiosasl.SASLFailure` exceptions are re-raised without modification. """

        sm = aiosasl.SASLStateMachine(intf)
        try:
            yield from mechanism.authenticate(sm, token)
            return True
        except aiosasl.SASLFailure as err:
            if err.opaque_error in self.AUTHENTICATION_FAILURES:
                raise aiosasl.AuthenticationFailure(
                    opaque_error=err.opaque_error,
                    text=err.text)
            elif err.opaque_error in self.MECHANISM_REJECTED_FAILURES:
                return False
            raise