text: import unittest
  from locker import User
  from locker import Credentials
  
  class TestClass(unittest.TestCase):
      """
      A Test class that defines test cases for the User class.
      """
      def setUp(self):
          """
          method that runs before each individual test methods run.
          """
          self.new_user = User('Ahmed','qwerty123')
  
      def test_init(self):
          """
          test case to check if the object has been initialized correctly
          """
          self.assertEqual(self.new_user.username,'Ahmed')
          self.assertEqual(self.new_user.password,'qwerty123')
  
      def test_save_user(self):
          """
          test case to test if a new user instance has been saved into the User list
          """
          self.new_user.save_user()
          self.assertEqual(len(User.user_list),1)
  class TestCredentials(unittest.TestCase):
      """
      test class that defines test cases for credentials class
      """ 
      def setUp(self):
          """
          method that runs before each individual credentials test methods run.
          """
          self.new_credential = Credentials('Gmail','Ahmed','qwerty177')
      def test_init(self):
          """
          test case to check if a new Credentials instance has been initialized correctly
          """
          self.assertEqual(self.new_credential.account,'Gmail')
          self.assertEqual(self.new_credential.userName,'Ahmed')
          self.assertEqual(self.new_credential.password,'qwerty177')
      def save_credential_test(self):
          """
          test case to test if object is saved into the credentials list.
          """
          self.new_credential.save_details()
          self.assertEqual(len(Credentials.credentials_list),1)
      def tearDown(self):
          '''
          method that does clean up after each test case has run.
          '''
          Credentials.credentials_list = []
      def test_save_many_accounts(self):
          '''
          test to check if we can save multiple credentials objects to our credentials list
          '''
          self.new_credential.save_details()
          test_credential = Credentials("Twitter","ahmedabdi","qwertyasdf") 
          test_credential.save_details()
          self.assertEqual(len(Credentials.credentials_list),2)
  
      def test_delete_credential(self):
          """
          test method to test if we can remove an account credentials from our credentials_list
          """
          self.new_credential.save_details()
          test_credential = Credentials("Twitter","ahmedabdi","qwertyasdf")
          test_credential.save_details()
  
          self.new_credential.delete_credentials()
          self.assertEqual(len(Credentials.credentials_list),1)
  
      def test_find_credential(self):
          """
          test to check if we can find a credential entry by account name and display the details of the credential
          """
          self.new_credential.save_details()
          test_credential = Credentials("Twitter","ahmedabdi","qwertyasdf") 
          test_credential.save_details()
  
          the_credential = Credentials.find_credential("Twitter")
  
          self.assertEqual(the_credential.account,test_credential.account)
  
      def test_credential_exist(self):
          """
          test to check if we can return a true or false based on whether we find the credential.
          """
          self.new_credential.save_details()
          the_credential = Credentials("Twitter", "ahmedabdi", "qwertyasdf")  
          the_credential.save_details()
          credential_is_found = Credentials.if_credential_exist("Twitter")
          self.assertTrue(credential_is_found)
  
      def test_display_all_saved_credentials(self):
          '''
          method that displays all the credentials that has been saved by the user
          '''
  
          self.assertEqual(Credentials.display_credentials(),Credentials.credentials_list)
  
  if __name__ == "__main__":
      unittest.main()