Extracts an unvalidated JSON web token from the given "Authorization"
        header value.

def get_raw_token(self, header):
        """
        Extracts an unvalidated JSON web token from the given "Authorization"
        header value.
        """
        parts = header.split()

        if len(parts) == 0:
            # Empty AUTHORIZATION header sent
            return None

        if parts[0] not in AUTH_HEADER_TYPE_BYTES:
            # Assume the header does not contain a JSON web token
            return None

        if len(parts) != 2:
            raise AuthenticationFailed(
                _('Authorization header must contain two space-delimited values'),
                code='bad_authorization_header',
            )

        return parts[1]