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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 revoke(self, template_address, account):
 """ Revoke a template already approved. The account needs to be owner of the templateManager contract to be able of revoke the template. :param template_address: Address of the template contract, str :param account: account revoking the template, Account :return: bool """

        try:
            revoked = self._keeper.template_manager.revoke_template(template_address, account)
            return revoked
        except ValueError as err:
            template_values = self._keeper.template_manager.get_template(template_address)
            if not template_values:
                logger.warning(f'Cannot revoke template since it does not exist: {err}')
                return False

            logger.warning(f'Only template admin or owner can revoke a template: {err}')
            return False