'Try to acquire the Netmiko session lock. If not available, wait in the queue until
the channel is available again.'

def _lock_netmiko_session(self, start=None):

    if (not start):
        start = time.time()
    while ((not self._session_locker.acquire(False)) and (not self._timeout_exceeded(start, u'The    netmiko    channel    is    not    available!'))):
        time.sleep(0.1)
    return True
