How to load urls one by one from an array in casperjs?

Question

PhantomJS

I make a function on Casper, opened the page, pressed the button, displayed the result.
I'm testing on windows and I'm confused by the starting pause before loading / rendering the 1st page, the second one is loaded immediately.
I understand that he spends time on the start of the program.
I’m thinking about how to iterate through the array of urls that I will pass and open the page, click, display one by one

casper.start('стартовый урл', function (response) {
    var av = list.split(',');
    for (i=0; i< av.length; i++){
        this.echo(av[i]);
        this.thenOpen('https://url/'+av[i],function () {
            takeShot(); // делаю скриншот1
            this.click('a.a2');
            takeShot(); // делаю скриншот2
        });
 
    }
}

As a result, it first works out the echo - it displays a list of urls, and then it just starts loading pages there ...
there is no sequence ...