public function getClientWithCOID(IRI $apiCoid) {
        $apiCoidString = (string)$apiCoid;
        if (!isset($this->apiClients[$apiCoidString])) {
            $this->apiClients[$apiCoidString] = self::createClient(
                $this->objectRetriever->getObject($apiCoid),
                $this->namespace);
        }

        return $this->apiClients[$apiCoidString];
    }