class Message{
    def List items;

    public Message(List items){
        this.items = replaceDes(items)
    }

    public Message(String string){
        items = deserialize(string)
    }

    public String serialize(){
        items.collect { it.toString().contains(',') ? it.replaceAll(',', '-'): it }.join(",")
    }

    public List deserialize(String serialized){
        replaceDes serialized.tokenize(",")
    }

    private List replaceDes(List des){
        des.collect { it.toString().contains('-') ? it.replaceAll('-', ',') : it }
    }

    public String toString(){
        'prvku: ' + items.size() + '\n' + items.join('\n')
    }
}


def pole1 = [1,2,'ahoj']
def zprava1 = new Message(pole1)
println "zprava 1: \n $zprava1 \n"

def pole2 = [3,4,'cau', zprava1.serialize()]
def zprava2 = new Message(pole2)
println "zprava 2: \n $zprava2 \n"

def zprava3 = new Message(zprava2.serialize())
println "zprava 3: \n $zprava3 \n"

def pole4 = [5,6,7,'zdar', zprava3.serialize()]
def zprava4 = new Message(pole4)
println "zprava 4: \n $zprava4 \n"

def zprava5 = new Message(zprava4.serialize())
println "zprava 5: \n $zprava5 \n"