Authorisation error with Google API php client - php

Question

I try to use Google API PHP client to make my application use its Google Drive account in offline way, because I dont want my application to redirect every time to google for getting authorisation.
So when I connect for the first time and recieve credentials with access_token and refresh_token I backup it and try to use it every time.
Problem is that it works till expiration and than , when API client tries to refresh acces token I'm keep getting this error:
Error refreshing the OAuth2 token, message: '{ "error" : "invalid_request", "error_description" : "Client must specify either client_id or client_assertion, not both" }
My stored credentials are in json form:
{"access_token":"XXX","token_type":"Bearer","expires_in":3600,"refresh_token":"XXX,"created":1406537500}
My code (taken from Google tutorials with some changes):
function exchangeCode($authorizationCode) {
try {
$client = new Google_Client();
$client->setClientId(self::$clientId);
$client->setClientSecret(self::$clientSacred);
$client->setRedirectUri(self::getRedirectURI());
$_GET['code'] = $authorizationCode;
return $client->authenticate();
} catch (Google_AuthException $e) {
echo 'An Google_AuthException occurred: ' . $e->getMessage();
throw new CodeExchangeException(null);
}
}
function getCredentials($authorizationCode, $state='') {
$emailAddress = '';
try {
$credentials = self::exchangeCode($authorizationCode);
$credentialsArray = json_decode($credentials, true);
if (isset($credentialsArray['refresh_token'])) {
self::storeCredentials($credentials);
return $credentials;
} else {
$credentials = self::getStoredCredentials();
$credentialsArray = json_decode($credentials, true);
if ($credentials != null &&
isset($credentialsArray['refresh_token'])) {
return $credentials;
}
}
} catch (CodeExchangeException $e) {
print 'An CodeExchangeException occurred during code exchange.';
$e->setAuthorizationUrl(self::getAuthorizationUrl($emailAddress, $state));
throw $e;
} catch (NoUserIdException $e) {
print 'No e-mail address could be retrieved.';
}
$authorizationUrl = self::getAuthorizationUrl($emailAddress, $state);
throw new NoRefreshTokenException($authorizationUrl);
}
function buildService($credentials) {
$apiClient = new Google_Client();
$apiClient->setUseObjects(true);
$apiClient->setAccessToken($credentials);
return new Google_DriveService($apiClient);
}
function test()
{
$credentials = self::getStoredCredentials();
if ( empty($credentials) )
{
if (!isset($_GET["code"]))
{
header("location:".self::getAuthorizationUrl("xxx#gmail.com", ''));
die();
}
$credentials = self::getCredentials($_GET["code"]);
echo "NEW: ".$credentials;
}
else
{
echo "STORED: ".$credentials;
}
$service = self::buildService($credentials);
}
The error happends in buildService method when its client object tries to refresh based on credentials passed.