public function setTargetAudience($audience_type, $list_type=null, $countries_array=null){

        if ($audience_type === "custom") {
            return $this->call('me/messenger_profile', [
                'target_audience' => [
                    'audience_type' => $audience_type,
                    'countries' => [
                        $list_type => $countries_array
                    ]
               ]
            ], self::TYPE_POST);
        } else {
            return $this->call('me/messenger_profile', [
                'target_audience' => [
                   'audience_type' => $audience_type
               ]
            ], self::TYPE_POST);
        }
    }