'Returns the time of the last modification to cobbler, made by any
API instance, regardless of the serializer type.'

def last_modified_time(self):

    if (not os.path.exists('/var/lib/cobbler/.mtime')):
        fd = os.open('/var/lib/cobbler/.mtime', (os.O_CREAT | os.O_RDWR), 128)
        os.write(fd, '0')
        os.close(fd)
        return 0
    fd = open('/var/lib/cobbler/.mtime')
    data = fd.read().strip()
    return float(data)
