text: from django.test import TestCase
  from customer.models import Customer
  
  
  class CustomerTestCase(TestCase):
      def setUp(self):
          Customer.objects.create(
              name="customer 1", address="test address", postcode="test"
          )
          self.customer = Customer.objects.get(name="customer 1")
  
      def test_customer(self):
          self.assertEqual(self.customer.__str__(), "customer 1")
  