code: def get_notification_subject_line(course_name, template_configuration=None):
      
      stock_subject_template = _('You\'ve been enrolled in {course_name}!')
      default_subject_template = getattr(
          settings,
          'ENTERPRISE_ENROLLMENT_EMAIL_DEFAULT_SUBJECT_LINE',
          stock_subject_template,
      )
      if template_configuration is not None and template_configuration.subject_line:
          final_subject_template = template_configuration.subject_line
      else:
          final_subject_template = default_subject_template
  
      try:
          return final_subject_template.format(course_name=course_name)
      except KeyError:
          pass
  
      try:
          return default_subject_template.format(course_name=course_name)
      except KeyError:
          return stock_subject_template.format(course_name=course_name)
docs: Get a subject line for a notification email.
  
      The method is designed to fail in a "smart" way; if we can't render a
      database-backed subject line template, then we'll fall back to a template
      saved in the Django settings; if we can't render _that_ one, then we'll
      fall through to a friendly string written into the code.
  
      One example of a failure case in which we want to fall back to a stock template
      would be if a site admin entered a subject line string that contained a template
      tag that wasn't available, causing a KeyError to be raised.
  
      Arguments:
          course_name (str): Course name to be rendered into the string
          template_configuration: A database-backed object with a stored subject line template