private Histogram createHistogram0() {
        // need serviceType of out link
        // ie. Tomcat -> Arcus: we need arcus type
        final LinkCallDataMap findMap = getLinkCallDataMap();
        AgentHistogramList outLinkList = findMap.getOutLinkList();
        return outLinkList.mergeHistogram(toNode.getServiceType().getHistogramSchema());
    }
A class that describes a relationship between apps in application map

@author netspider
@author emeroad
@author HyunGil Jeong
web/src/main/java/com/navercorp/pinpoint/web/applicationmap/link/Link.java