Customer/EventListener/CustomerGroupListener.php
public function onInsert(ResourceEventInterface $event)
    {
        $group = $this->getCustomerGroupFromEvent($event);

        $this->fixDefault($group);
    }
public function onInsert(ResourceEventInterface $event)
    {
        $group = $this->getCustomerGroupFromEvent($event);

        $this->fixDefault($group);
    }
Insert event handler.

@param ResourceEventInterface $event