Save this wait_time condition into an xml.dom.Element object.

def save_xml(self, doc, element):
        '''Save this wait_time condition into an xml.dom.Element object.'''
        super(WaitTime, self).save_xml(doc, element)
        new_element = doc.createElementNS(RTS_NS, RTS_NS_S + 'WaitTime')
        new_element.setAttributeNS(RTS_NS, RTS_NS_S + 'waitTime',
                str(self.wait_time))
        element.appendChild(new_element)