private boolean usedLink(Link link) {
        final List<Node> nodeList = this.linkMap.findNode(link);
        if (CollectionUtils.isEmpty(nodeList)) {
            return false;
        }
        int size = nodeList.size();
        if (size > 1) {
            boolean result = false;
            for (Node node : nodeList) {
                if (putNodeToLink(link, node, true)) {
                    result = true;
                }
            }
            return result;
        } else if (size == 1) {
            Node node = nodeList.get(0);
            if (putNodeToLink(link, node, false)) {
                return true;
            }
        }
        return false;
    }
@author netspider
@author emeroad
@author jaehong.kim
web/src/main/java/com/navercorp/pinpoint/web/calltree/span/SpanAligner.java