Are you sure the assignment to $response is correct as static::$xsollaClient->C...sdk_coupon_', false)))) (which targets Xsolla\SDK\API\XsollaClient::CreateCoupon()) seems to always return null.
This check looks for function or method calls that always return null and whose
return value is assigned to a variable.
This check looks for function or method calls that always return null and whose return value is assigned to a variable.
The method
getObject()
can return nothing but null, so it makes no sense to assign that value to a variable.The reason is most likely that a function or method is imcomplete or has been reduced for debug purposes.