How to use the b2sdk.exception.Unauthorized function in b2sdk

def _assert_account_auth(
        self, api_url, account_auth_token, account_id, capability, bucket_id=None, file_name=None
    ):
        key_sim = self.auth_token_to_key.get(account_auth_token)
        assert key_sim is not None
        assert api_url == self.API_URL
        assert account_id == key_sim.account_id
        if account_auth_token in self.expired_auth_tokens:
            raise InvalidAuthToken('auth token expired', 'auth_token_expired')
        if capability not in key_sim.capabilities:
            raise Unauthorized('', 'unauthorized')
        if key_sim.bucket_id_or_none is not None and key_sim.bucket_id_or_none != bucket_id:
            raise Unauthorized('', 'unauthorized')
        if key_sim.name_prefix_or_none is not None:
            if file_name is not None and not file_name.startswith(key_sim.name_prefix_or_none):
                raise Unauthorized('', 'unauthorized')

if set(capabilities) != set(ALL_CAPABILITIES):
            key_messages.append("with capabilities '" + ','.join(capabilities) + "'")
        if bucket_name is not None:
            key_messages.append("restricted to bucket '" + bucket_name + "'")
        if name_prefix is not None:
            key_messages.append("restricted to files that start with '" + name_prefix + "'")
        if not key_messages:
            key_messages.append('with no restrictions')

        # Make a new message
        new_message = unauthorized.message
        if new_message == '':
            new_message = 'unauthorized'
        new_message += ' for application key ' + ', '.join(key_messages)

        return Unauthorized(new_message, unauthorized.code)

def _assert_account_auth(
        self, api_url, account_auth_token, account_id, capability, bucket_id=None, file_name=None
    ):
        key_sim = self.auth_token_to_key.get(account_auth_token)
        assert key_sim is not None
        assert api_url == self.API_URL
        assert account_id == key_sim.account_id
        if account_auth_token in self.expired_auth_tokens:
            raise InvalidAuthToken('auth token expired', 'auth_token_expired')
        if capability not in key_sim.capabilities:
            raise Unauthorized('', 'unauthorized')
        if key_sim.bucket_id_or_none is not None and key_sim.bucket_id_or_none != bucket_id:
            raise Unauthorized('', 'unauthorized')
        if key_sim.name_prefix_or_none is not None:
            if file_name is not None and not file_name.startswith(key_sim.name_prefix_or_none):
                raise Unauthorized('', 'unauthorized')

elif status == 400 and code == "missing_part":
        return MissingPart(post_params.get('fileId'))
    elif status == 400 and code == "part_sha1_mismatch":
        return PartSha1Mismatch(post_params.get('fileId'))
    elif status == 400 and code == "bad_request":
        matcher = UPLOAD_TOKEN_USED_CONCURRENTLY_ERROR_MESSAGE_RE.match(message)
        if matcher is not None:
            token = matcher.group('token')
            return UploadTokenUsedConcurrently(token)
        return BadRequest(message, code)
    elif status == 400:
        return BadRequest(message, code)
    elif status == 401 and code in ("bad_auth_token", "expired_auth_token"):
        return InvalidAuthToken(message, code)
    elif status == 401:
        return Unauthorized(message, code)
    elif status == 403 and code == "storage_cap_exceeded":
        return StorageCapExceeded()
    elif status == 409:
        return Conflict()
    elif status == 416 and code == "range_not_satisfiable":
        return UnsatisfiableRange()
    elif status == 429:
        return TooManyRequests(retry_after_seconds=response_headers.get('retry-after'))
    elif 500 <= status < 600:
        return ServiceError('%d %s %s' % (status, code, message))
    return UnknownError('%d %s %s' % (status, code, message))

def __init__(self, message, code):
        super(Unauthorized, self).__init__()
        self.message = message
        self.code = code