docs: def get_user(self, username):
          """
          Given the verified username, look up and return the
          corresponding user account if it exists, or ``None`` if it
          doesn't.
  
          """
          User = get_user_model()  # noqa
          try:
              user = User.objects.get(**{
                  User.USERNAME_FIELD: username,
                  'is_active': False
              })
              return user
          except User.DoesNotExist:
              return None