How to modify a list of warranty periods

At the present moment a list of warranty periods is hard-coded in the file. In order to modify it you need to do the following steps.

Instructions for Opencart 2

Find this file:
admin\model\catalog\product_warranties.php

Find this function in that file:

public function getWarrantyPeriods() {
$periods = array(
    '30d' => '30 days',
    '60d' => '60 days',
    '90d' => '90 days',
    '1y'  => '1 year',
    '2y'  => '2 years',
    '3y'  => '3 years',
    '5y'  => '5 years',
    'unlimited' => $this->language->get('Unlimited'),
);

And insert/remove lines similar to showed there. For example, if you need to add a new ‘10 years period’ you need to add a new line:

‘10y’ => ‘10 years’,