@GuardedBy("lock")
private boolean waitForQueue() {
    long timeout = TASK_WAIT_NANOS;

    while (queue.isEmpty()) {
        if (timeout <= 0) {
            return false;
        }

        try {
            timeout = notEmpty.awaitNanos(timeout);
        } catch (InterruptedException e) {
            // The executor is probably shutting down so log as debug.
            LOG.debug("{}: Interrupted trying to remove from {} worker's queue", getIdentifier(), key);
            return false;
        }
    }

    return true;
}