[XTemplates] How to get an item in list with his index

Hello,

I've a template i do not found anything explaining how to get an item with his index in a list.

I passed a List<Person> persons that contain: List<Person> kids.

Code:

public class Person {
  private String name;
  private List<Person> kids;
  public Person(String name, List<Person> kids) {
    this.name = name;
    this.kids = kids;
  }
  public String getName() {
    return name;
  }
  public List<Person> getKids() {
    return kids;
  }
}

The template below is not working, what is wrong ?

Code:

<div>
  <tpl for='.'>
    <p>
      {#}. Hello {name}! Your first kid is: {kids[0].name} and your last kids is {kids[kids.size-1].name}
    </p>
  </tpl>
</div>

I'm using GXT 3.1, Thank for reading.