Mark asStripe... methods internal

src/Billable.php

@@ -756,6 +756,7 @@ public function createOrGetStripeCustomer(array $options = [])
     /**
      * Get the Stripe customer for the model.
      *
+     * @internal
      * @return \Stripe\Customer
      */
     public function asStripeCustomer()

src/Invoice.php

@@ -320,6 +320,7 @@ public function downloadAs($filename, array $data)
     /**
      * Get the Stripe invoice instance.
      *
+     * @internal
      * @return \Stripe\Invoice
      */
     public function asStripeInvoice()

src/InvoiceItem.php

@@ -115,6 +115,7 @@ protected function formatAmount($amount)
     /**
      * Get the underlying Stripe invoice item.
      *
+     * @internal
      * @return \Stripe\StripeObject
      */
     public function asStripeInvoiceItem()

src/Payment.php

@@ -116,6 +116,7 @@ public function validate()
     /**
      * The Stripe PaymentIntent instance.
      *
+     * @internal
      * @return \Stripe\PaymentIntent
      */
     public function asStripePaymentIntent()

src/PaymentMethod.php

@@ -46,6 +46,7 @@ public function delete()
     /**
      * Get the Stripe PaymentMethod instance.
      *
+     * @internal
      * @return \Stripe\PaymentMethod
      */
     public function asStripePaymentMethod()

src/Subscription.php

@@ -663,6 +663,7 @@ public function latestPayment()
     /**
      * Get the subscription as a Stripe subscription object.
      *
+     * @internal
      * @param  array  $expand
      * @return \Stripe\Subscription
      */