lib/mail/TrackingSettings.php
public function jsonSerialize()
    {
        return array_filter(
            [
                'click_tracking' => $this->getClickTracking(),
                'open_tracking' => $this->getOpenTracking(),
                'subscription_tracking' => $this->getSubscriptionTracking(),
                'ganalytics' => $this->getGanalytics()
            ],
            function ($value) {
                return $value !== null;
            }
        ) ?: null;
    }
public function jsonSerialize()
    {
        return array_filter(
            [
                'click_tracking' => $this->getClickTracking(),
                'open_tracking' => $this->getOpenTracking(),
                'subscription_tracking' => $this->getSubscriptionTracking(),
                'ganalytics' => $this->getGanalytics()
            ],
            function ($value) {
                return $value !== null;
            }
        ) ?: null;
    }
public function jsonSerialize ( ) { return array_filter ( [ 'click_tracking' => $ this -> getClickTracking ( ) , 'open_tracking' => $ this -> getOpenTracking ( ) , 'subscription_tracking' => $ this -> getSubscriptionTracking ( ) , 'ganalytics' => $ this -> getGanalytics ( ) ] , function ( $ value ) { return $ value !== null ; } ) ? : null ; }
Return an array representing a TrackingSettings object for the Twilio SendGrid API

@return null|array
Return an array representing a TrackingSettings object for the Twilio SendGrid API