def METHOD_NAME():
    global vncserver_addr
    if vncserver_addr != -1:
        print('VNC server already running at: ' + vncserver_addr)
        return
    addr = 0
    while True:
        try:
            addr += 1
            out = subprocess.check_output(['vncserver', ':' + str(addr)],
                                          stderr=subprocess.STDOUT)
            os.environ['DISPLAY'] = ':' + str(addr)
            break
        except subprocess.CalledProcessError:
            pass
    vncserver_addr = addr