Function being called more times than expected

Function being called more times than expected

In my source code i have a function appendRow that i only call 4 times in
the constructor defined at line 50 :
var Layout = function() {
this.appendRow();
this.appendRow();
this.appendRow();
this.appendRow();
};
And called at line 242 :
$(function() {
window.lay = new Layout();
$('#test').html( lay.toHtml() );
});
But some some reason i just don't understand it is being called 9 times.
I've searched for other calls to it in the source code but there aren't
any other, and the constructor is only called once.
Here is the source code. Any idea please ? This is making me crazy.
Thanks for your help !