def METHOD_NAME():
    auth_header = LegacySessionTokenAuthenticator(
        config=config,
        parameters=parameters,
        api_url=input_instance_api_url,
        username=input_username,
        password=input_password,
        session_token=input_session_token,
        header=header,
        session_token_response_key=session_token_response_key,
        login_url=login_url,
        validate_session_url=validate_session_url,
    ).auth_header
    assert auth_header == "X-App-Session"