def get_conditions(self, service_id):
        """
        Build a Conditions XML block for a SAML 1.1 Assertion.
        """
        conditions = etree.Element('Conditions')
        conditions.set('NotBefore', self.instant())
        conditions.set('NotOnOrAfter', self.instant(offset=30))
        restriction = etree.SubElement(conditions, 'AudienceRestrictionCondition')
        audience = etree.SubElement(restriction, 'Audience')
        audience.text = service_id
        return conditions
Build a Conditions XML block for a SAML 1.1 Assertion.