def compose_envars(auth_response):
    """Given response from assume-role, compose shell commands for setting auth
    environment variables."""
    creds = auth_response["Credentials"]
    envars = {
        "AWS_ACCESS_KEY_ID": creds["AccessKeyId"],
        "AWS_SECRET_ACCESS_KEY": creds["SecretAccessKey"],
        "AWS_SESSION_TOKEN": creds["SessionToken"],
    }

    return "\n".join(f"export {k}={v}" for k, v in envars.items())