old_contents: """
  Base class for testing a web application.
  """
  
  from unittest import TestCase
  from abc import ABCMeta, abstractproperty, abstractmethod
  import os.path
  from uuid import uuid4
  
  from e2e_framework.web_app_ui import WebAppUI, WrongPageError
  
  
  class WebAppTest(TestCase):
      """
      Base class for testing a web application.
      """
  
      __metaclass__ = ABCMeta
  
      # Execute tests in parallel!
      _multiprocess_can_split_ = True
  
      # The browser to use when testing the web app
      TEST_BROWSER = "chrome"
  
      # Subclasses can use this property
      # to access the `WebAppUI` object under test
      ui = None
  
      def setUp(self):
  
          # Set up the page objects
          # This will start the browser, so add a cleanup
          self.ui = WebAppUI(self.TEST_BROWSER, self.page_object_classes)
          self.addCleanup(self.ui.quit_browser)
  
      @abstractproperty
      def page_object_classes(self):
          """
          Subclasses override this to return a list
          of `PageObject` subclasses to visit
          during the test.
          """
          return []
  
  
  class TestCredentials(object):
      """
      Encapsulate fake user information.
      """
  
      BASE_EMAIL_USER = "will"
      EMAIL_DOMAIN = "edx.org"
  
      def __init__(self):
          """
          Initialize new credentials.
          """
  
          unique_id = str(uuid4())[0:8]
  
          self._username = "{0}_{1}".format(
              self.BASE_EMAIL_USER, unique_id
          )
  
          self._email = "{0}+{1}@{2}".format(
              self.BASE_EMAIL_USER, unique_id, self.EMAIL_DOMAIN
          )
  
          self._full_name = "{0} {1}".format(
              self.BASE_EMAIL_USER, unique_id
          )
  
          self._password = unique_id
  
      @property
      def username(self):
          return self._username
  
      @property
      def email(self):
          return self._email
  
      @property
      def full_name(self):
          return self._full_name
  
      @property
      def password(self):
          return self._password
  
new_contents: """
  Base class for testing a web application.
  """
  
  from unittest import TestCase
  from abc import ABCMeta, abstractproperty, abstractmethod
  import os.path
  from uuid import uuid4
  
  from e2e_framework.web_app_ui import WebAppUI, WrongPageError
  
  
  class WebAppTest(TestCase):
      """
      Base class for testing a web application.
      """
  
      __metaclass__ = ABCMeta
  
      # Execute tests in parallel!
      _multiprocess_can_split_ = True
  
      # Subclasses can use this property
      # to access the `WebAppUI` object under test
      ui = None
  
      def setUp(self):
  
          # Set up the page objects
          # This will start the browser, so add a cleanup
          self.ui = WebAppUI(self.page_object_classes)
          self.addCleanup(self.ui.quit_browser)
  
      @abstractproperty
      def page_object_classes(self):
          """
          Subclasses override this to return a list
          of `PageObject` subclasses to visit
          during the test.
          """
          return []
  
  
  class TestCredentials(object):
      """
      Encapsulate fake user information.
      """
  
      BASE_EMAIL_USER = "will"
      EMAIL_DOMAIN = "edx.org"
  
      def __init__(self):
          """
          Initialize new credentials.
          """
  
          unique_id = str(uuid4())[0:8]
  
          self._username = "{0}_{1}".format(
              self.BASE_EMAIL_USER, unique_id
          )
  
          self._email = "{0}+{1}@{2}".format(
              self.BASE_EMAIL_USER, unique_id, self.EMAIL_DOMAIN
          )
  
          self._full_name = "{0} {1}".format(
              self.BASE_EMAIL_USER, unique_id
          )
  
          self._password = unique_id
  
      @property
      def username(self):
          return self._username
  
      @property
      def email(self):
          return self._email
  
      @property
      def full_name(self):
          return self._full_name
  
      @property
      def password(self):
          return self._password
  
subject: Remove reference to TEST_BROWSER