I have a question about delegate Class !

In the a dashboard page, i use :
- Code: Select all
{foreach from=$Groups item=groups}
<li><a href="{$groups->getURL('-action=view')}#embed"> {$groups->getTitle()} </a><br /><em></em></li>
{/foreach}
It works fine, but i want to test something and i have to use a method like isSubCat() in Groups.php.
Can you say me why i can't use a method which is not overide ?
THank you !