def _stripe_object_to_subscription_items(cls, target_cls, data, subscription):
		"""
		Retrieves SubscriptionItems for a subscription.

		If the subscription item doesn't exist already then it is created.

		:param target_cls: The target class to instantiate per invoice item.
		:type target_cls: ``SubscriptionItem``
		:param data: The data dictionary received from the Stripe API.
		:type data: dict
		:param invoice: The invoice object that should hold the invoice items.
		:type invoice: ``djstripe.models.Subscription``
		"""

		items = data.get("items")
		if not items:
			return []

		subscriptionitems = []
		for item_data in items.get("data", []):
			item, _ = target_cls._get_or_create_from_stripe_object(item_data, refetch=False)
			subscriptionitems.append(item)

		return subscriptionitems
Retrieves SubscriptionItems for a subscription.

		If the subscription item doesn't exist already then it is created.

		:param target_cls: The target class to instantiate per invoice item.
		:type target_cls: ``SubscriptionItem``
		:param data: The data dictionary received from the Stripe API.
		:type data: dict
		:param invoice: The invoice object that should hold the invoice items.
		:type invoice: ``djstripe.models.Subscription``