Method: Retrieves the subscription item with the given ID.
Source Files: includes/lib/stripe-php/lib/Service/SubscriptionItemService.php
Method: Deletes an item from the subscription. Removing a subscription item from a subscription will not cancel the subscription.
Method: For the specified subscription item, returns a list of summary objects. Each object in the list provides usage information that’s been summarized from multiple usage records and over a subscription billing period (e.g., 15 usage records in the month of September).