Google::getInterface

public function getInterface()
{
	if($this->authInterface === null)
	{
		$this->authInterface = new CGoogleOAuthInterface($this->engine['CLIENT_ID'], $this->engine['CLIENT_SECRET']);
		$this->authInterface->setScope($this->getScope());

		if($this->engineSettings['AUTH'])
		{
			$this->authInterface->setToken($this->engineSettings['AUTH']['access_token']);
			$this->authInterface->setRefreshToken($this->engineSettings['AUTH']['refresh_token']);
			$this->authInterface->setAccessTokenExpires($this->engineSettings['AUTH']['expires_in']);
		}
	}

	return $this->authInterface;
}