@Override
    public boolean equals(Object obj) {
        if (this == obj)
            return true;
        if (obj == null)
            return false;
        if (getClass() != obj.getClass())
            return false;
        LinkingObject other = (LinkingObject) obj;
        if (linkingObjectIdentifier == null) {
            if (other.linkingObjectIdentifier != null)
                return false;
        } else if (!linkingObjectIdentifier.equals(other.linkingObjectIdentifier))
            return false;
        if (linkingObjectRole == null) {
            if (other.linkingObjectRole != null)
                return false;
        } else if (!linkingObjectRole.equals(other.linkingObjectRole))
            return false;
        return true;
    }