Access variable opencart 2

Hello,
i want to access $text_wishlist in cart.tpl. I was trying to take code for this variable from header.php to cart.php like this:

// Wishlist
if ($this->customer->isLogged()) {
$this->load->model('account/wishlist');

$data['text_wishlist'] = sprintf($this->language->get('text_wishlist'), $this->model_account_wishlist->getTotalWishlist());
} else {
$data['text_wishlist'] = sprintf($this->language->get('text_wishlist'), (isset($this->session->data['wishlist']) ? count($this->session->data['wishlist']) : 0));
}
BUT its not working. Even $data['text_wishlist'] = "Ahoj"; is not working. Please, what am I doing wrong and how can i access $text_wishlist variable in cart.tpl?

Very thanks :)