Where to write hook_commerce_payment_method_info() in drupal8? I am migrating one of the drupal commerce related module from Drupal-7 to drupal-8.As I am newbie to D8, struggling to get proper structure in drupal-8. I have a hook that is hook_commerce_payment_method_info(). I am confused to where to write this hook. I am guessing it will be in .module file. please share your suggestions to me. So that I can move in right direction. Thanks in advance.
Payment methods are now called Payment gateways and they are plugins, like anything else.

So, look for the @CommercePaymentGateway annotation, like in this example: https://github.com/drupalcommerce/commerce/blob/8.x-2.x/modules/payment_example/src/Plugin/Commerce/PaymentGateway/Onsite.php and the others in that folder.