externalDoc = $externalDoc; $this->overwrite = $overwrite; } public function describe(OA\OpenApi $api) { $externalDoc = $this->getExternalDoc(); if (!empty($externalDoc)) { Util::merge($api, $externalDoc, $this->overwrite); } } private function getExternalDoc() { if (is_callable($this->externalDoc)) { return call_user_func($this->externalDoc); } return $this->externalDoc; } }