old_contents: from django.test import TestCase
  from member.models import Member
  from datetime import date
  
  
  class MemberTestCase(TestCase):
  
      def setUp(self):
          Member.objects.create(firstname='Katrina', birthdate=date(1980, 4, 19))
  
      def test_age_on_date(self):
          """The age on given date is properly computed"""
          katrina = Member.objects.get(firstname='Katrina')
          self.assertEqual(katrina.age_on_date(date(2016, 4, 19)), 36)
          self.assertEqual(katrina.age_on_date(date(1950, 4, 19)), 0)
          self.assertEqual(katrina.age_on_date(katrina.birthdate), 0)
  
new_contents: from django.test import TestCase
  from member.models import Member, Client
  from datetime import date
  
  
  class MemberTestCase(TestCase):
  
      def setUp(self):
          Member.objects.create(firstname='Katrina', lastname='Heide', birthdate=date(1980, 4, 19))
  
      def test_age_on_date(self):
          """The age on given date is properly computed"""
          katrina = Member.objects.get(firstname='Katrina')
          self.assertEqual(katrina.age_on_date(date(2016, 4, 19)), 36)
          self.assertEqual(katrina.age_on_date(date(1950, 4, 19)), 0)
          self.assertEqual(katrina.age_on_date(katrina.birthdate), 0)
  
      def test_str_is_fullname(self):
          """The member model must be rendered using the firstname and the lastname"""
          member = Member.objects.get(firstname='Katrina')
          self.assertEqual(str(member), 'Katrina Heide')
  
subject: Add unit test on __str__ function