'Returns the disk mounted at device
:returns LivirtConfigGuestDisk: mounted at device or None'

def get_disk(self, device):

    try:
        doc = etree.fromstring(self._domain.XMLDesc(0))
    except Exception:
        return None
    node = doc.find(("./devices/disk/target[@dev='%s'].." % device))
    if (node is None):
        node = doc.find(("./devices/disk/source[@file='%s'].." % device))
    if (node is not None):
        conf = vconfig.LibvirtConfigGuestDisk()
        conf.parse_dom(node)
        return conf
