| ⇢ | A | ReferralEvent added | |
| ⇢ | A | Referral added | |
| A | ↘ | B | CallbackEventFactory got worse |
| ⇢ | A | ReferralEvent::__construct() added | |
| ⇢ | A | Referral::__construct() added | |
| ⇢ | A | CallbackEventFactory::createReferralEvent() added | |
| ⇢ | A | ReferralEvent::getTimestamp() added | |
| ⇢ | A | ReferralEvent::getReferral() added | |
| ⇢ | A | ReferralEvent::getName() added | |
| ⇢ | A | Postback::getReferral() added | |
| ⇢ | A | Postback::hasReferral() added | |
| ⇢ | A | Referral::getRef() added | |
| ⇢ | A | Referral::getSource() added | |
| ⋮ | view more | ||
| C | ↘ | D | CallbackEventFactory::create() got worse |