public function loadKeys($configuredKeys, string $usage = null) : void
    {
        foreach ($configuredKeys as $keyData) {
            if (isset($keyData['X509Certificate'])) {
                $key = new X509($keyData);
            } else {
                $key = new Key($keyData);
            }

            if ($usage && !$key->canBeUsedFor($usage)) {
                continue;
            }

            $this->loadedKeys->add($key);
        }
    }