Can't add new(custom) button action Helper list

[_brewery_Dev]

Hello, i am developing a payment module and use HelperList class for listing all transaction made by my module. I wish add new(custom) button to actions array. Here is my functionality 

$helper = new HelperList();

$helper->shopLinkType = '';
$helper->simple_header = false;
$helper->identifier = 'id_transaction';
$helper->actions = array('delete', 'some_new_button');
$helper->show_toolbar = false;
$helper->no_link = true; 

$helper->title = $this->displayName . '- refused requests';
$helper->table = $this->name;

but 'some_new_button' don't show in actions buttons. Why any ideas when I wrong? Thanks ! Cheers !

[Smart-Modules]

In 1.6 this worked:

 

$helper->toolbar_btn['new'] = array(
            'href' => AdminController::$currentIndex.'&configure='.$this->name.'&add'.$this->name.'&token='.Tools::getAdminTokenLite('AdminModules'),
            'desc' => $this->l('Add new...')
);

Maybe you can try to adapt it to your code