src/Doctrine/Listener.php
private function scheduleForDeletion($object)
    {
        if ($identifierValue = $this->propertyAccessor->getValue($object, $this->config['identifier'])) {
            $this->scheduledForDeletion[] = !is_scalar($identifierValue) ? (string) $identifierValue : $identifierValue;
        }
    }
private function scheduleForDeletion($object)
    {
        if ($identifierValue = $this->propertyAccessor->getValue($object, $this->config['identifier'])) {
            $this->scheduledForDeletion[] = !is_scalar($identifierValue) ? (string) $identifierValue : $identifierValue;
        }
    }
Record the specified identifier to delete. Do not need to entire object.

@param object $object