Given the verified username, look up and return the
        corresponding user account if it exists, or ``None`` if it
        doesn't.

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