public RSNode getNext() {
        RSNode node = this.node;

        if (node == getHead()) {
            this.node = null;
            return null;
        }
        this.node = node.getNext();

        return node;
    }

    public RSNode getPrevious() {
        RSNode node = this.node;

        if (node == getHead()) {
            this.node = null;
            return null;
        }
        this.node = node.getNext();

        return node;
    }