Doctrine\ODM\MongoDB\Tools\DocumentGenerator::generateDocumentLifecycleCallbackMethods PHP Method

    private function generateDocumentLifecycleCallbackMethods(ClassMetadataInfo $metadata)
    {
        if (empty($metadata->lifecycleCallbacks)) {
            return '';
        }
        $methods = array();
        foreach ($metadata->lifecycleCallbacks as $event => $callbacks) {
            foreach ($callbacks as $callback) {
                if ($code = $this->generateLifecycleCallbackMethod($event, $callback, $metadata)) {
                    $methods[] = $code;
                }
            }
        }
        return implode("\n\n", $methods);
    }