def METHOD_NAME(self):
    """Check tcpdump uses nonblocking next_line"""
    self.ping_all_when_learned()
    from_host = self.net.hosts[0]
    to_host = self.net.hosts[1]
    tcpdump_filter = "icmp"
    tcpdump_helper = TcpdumpHelper(
        to_host,
        tcpdump_filter,
        [lambda: from_host.cmd("ping -c10 %s" % to_host.IP())],
        blocking=False,
        packets=None,
    )
    count = 0
    while tcpdump_helper.next_line():
        count = count + 1
        self.assertTrue(count < 10, "Too many ping results before noblock")
    self._terminate_with_nonzero(tcpdump_helper)