/**
* Gets new auth token to replace expired one.
* @param OAuthToken $token expired auth token.
* @return OAuthToken new auth token.
*/
public function refreshAccessToken(OAuthToken $token)
{
$params = ['client_id' => $this->clientId, 'client_secret' => $this->clientSecret, 'grant_type' => 'refresh_token'];
$params = array_merge($token->getParams(), $params);
$response = $this->sendRequest('POST', $this->tokenUrl, $params);
return $response;
}