public Application getFilterApplication() {
        // User link: need to look at WAS, not from
        // Since User is a virtual link, we cannot filter by User
        if (fromNode.getServiceType() == ServiceType.USER) {
            return toNode.getApplication();
        }
        // same goes for virtual queue nodes
        if (!fromNode.getServiceType().isWas() && fromNode.getServiceType().isQueue()) {
            return toNode.getApplication();
        }
        return fromNode.getApplication();
    }
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