PayPal\Auth\Openid\PPOpenIdUserinfo::setUserId PHP Method

Subject - Identifier for the End-User at the Issuer.

public setUserId ( string $user_id )
$user_id	string

    public function setUserId($user_id)
    {
        $this->user_id = $user_id;
        return $this;
    }

PPOpenIdUserinfo