@Override
    public int hashCode() {
        final int prime = 31;
        int result = 1;
        result = prime * result + ((newLine == null) ? 0 : newLine.hashCode());
        result = prime * result + ((oldLine == null) ? 0 : oldLine.hashCode());
        result = prime * result + ((tag == null) ? 0 : tag.hashCode());
        return result;
    }