protected function getFacebookObject() {
		// keep only one instance during a session
		if (is_object($this->fb)) {
			return $this->fb;
		}
		
		$fb = new \Facebook\Facebook([
			'app_id' => $this->options['api_key'],
			'app_secret' => $this->options['secret_key'],
			'default_graph_version' => 'v3.0',
			]);
		
		$this->fb = $fb;
		
		return $fb;
	}