class ClientList implements ClientExpression<ClientList> {

    @Override
    public String toString() {

        if (this.items == null || this.items.isEmpty()) {
            return "()";
        }

        StringBuilder sb = new StringBuilder("(");
        boolean isFirst = true;
        for (ClientExpression expression : this.items) {
            if(isFirst){
                isFirst = false;
            } else {
                sb.append(", ");
            }
            sb.append(expression.toString());
        }
        sb.append(")");
        return sb.toString();
    }

    public  ClientList();
    public  ClientList(List<ClientExpression> expressions);
    public  ClientList(ClientList source);

}