LauLamanApps / iZettleApi

        $this->clientSecret = $clientSecret;

    }

    public function getFromUserLogin(string $username, string $password): AccessToken

    {

        $options = [

            'form_params' => [

                'grant_type' => self::API_ACCESS_TOKEN_PASSWORD_GRANT,

                'client_id' => $this->clientId,

                'client_secret' => $this->clientSecret,

                'username' => $username,

                'password' => $password

            ],

        ];

        return $this->getAccessTokenFromData($this->makeRequest(self::API_ACCESS_TOKEN_REQUEST_URL, $options));

    }

    public function refresh(AccessToken $accessToken): AccessToken

    {

        return $this->getAccessTokenFromData($this->makeRequest(self::API_ACCESS_TOKEN_REQUEST_URL, $options));

    }

    public function refresh(AccessToken $accessToken): AccessToken

    {

        $options = [

            'form_params' => [

                'grant_type' => self::API_ACCESS_TOKEN_REFRESH_TOKEN_GRANT,

                'client_id' => $this->clientId,

                'client_secret' => $this->clientSecret,

                'refresh_token' => $accessToken->getRefreshToken()

            ],

        ];

        return $this->getAccessTokenFromData($this->makeRequest(self::API_ACCESS_TOKEN_REFRESH_TOKEN_URL, $options));

    }

    private function makeRequest($url, $options): array

    {