src/Base/Component.php
public function hasEventListeners($event) {
        return !empty($this->listeners[$event]) || !empty($this->onceListeners[$event]);
    }
public function hasEventListeners($event) {
        return !empty($this->listeners[$event]) || !empty($this->onceListeners[$event]);
    }
Check attached event listeners for particular event
@param string $event
@return bool