def METHOD_NAME(self, host, ip, interface, server_id):
    # Build command
    cmd = "speedtest -f json -p no -A -P 8 "
    if host:
        cmd += " --host={}".format(host)
    if ip:
        cmd += " --ip={}".format(ip)
    if interface:
        cmd += " --interface={}".format(interface)
    if server_id:
        cmd += " --server-id={}".format(server_id)
    return cmd