old_contents: from django.conf import settings
  import stripe
  
  stripe.api_key = settings.STRIPE_API_KEY
  stripe.api_version = "2018-10-31"
  
  
  class StripeGateway:
      """A gateway to Stripe
  
      This insulates the rest of the system from Stripe errors
      and configures the Stripe module with the API key.
      """
  
      def create_customer(self, user: settings.AUTH_USER_MODEL, stripe_token: str) -> str:
          """Add a user to Stripe and join them to the plan."""
          # Let this fail on purpose. If it fails, the error monitoring system
          # will log it and I'll learn how to harden it for the conductor env.
          customer = stripe.Customer.create(email=user.email, source=stripe_token)
          stripe.Subscription.create(
              customer=customer.id,
              items=[{"plan": settings.STRIPE_PLAN}],
              trial_from_plan=True,
          )
          return customer.id
  
  
  stripe_gateway = StripeGateway()
  
new_contents: from django.conf import settings
  import stripe
  
  stripe.api_key = settings.STRIPE_API_KEY
  
  
  class StripeGateway:
      """A gateway to Stripe
  
      This insulates the rest of the system from Stripe errors
      and configures the Stripe module with the API key.
      """
  
      def create_customer(self, user: settings.AUTH_USER_MODEL, stripe_token: str) -> str:
          """Add a user to Stripe and join them to the plan."""
          # Let this fail on purpose. If it fails, the error monitoring system
          # will log it and I'll learn how to harden it for the conductor env.
          customer = stripe.Customer.create(email=user.email, source=stripe_token)
          stripe.Subscription.create(
              customer=customer.id,
              items=[{"plan": settings.STRIPE_PLAN}],
              trial_from_plan=True,
          )
          return customer.id
  
  
  stripe_gateway = StripeGateway()
  
subject: Remove pinned Stripe API version.