@Override
    public boolean equals(Object o) {
        if (this == o) return true;
        if (o == null || getClass() != o.getClass()) return false;

        Link that = (Link) o;

        if (!fromNode.equals(that.fromNode)) return false;
        if (!toNode.equals(that.toNode)) return false;

        return true;
    }
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