Return a list of sham.network.interfaces.NetworkInterface
        describing all the interfaces this VM has

def get_interfaces(self):
        """
        Return a list of sham.network.interfaces.NetworkInterface
        describing all the interfaces this VM has
        """
        interfaces = self.xml.find('devices').iter('interface')
        iobjs = []
        for interface in interfaces:
            _type = interface.attrib['type']
            mac = interface.find('mac').attrib['address']
            source = interface.find('source').attrib[_type]
            model = interface.find('model').attrib['type']
            iobjs.append(NetworkInterface(_type, mac, source, model))
        return iobjs