| ⇢ | A | BackButton added |
| ⇢ | A | BackButton::run() added | |
| ⇢ | A | BackButton::getReferrerUrl() added | |
| ⇢ | A | BackButton::getLabel() added | |
| ⇢ | A | BackButton::registerClientScript() added | |
| ⇢ | A | BackButton::getStep() added | |
| ⇢ | A | BackButton::getIdentifier() added | |
| ⇢ | A | BackButton::getCurrentUrl() added |