SAML2\Configuration\ServiceProvider::getPrivateKey PHP Method

    public function getPrivateKey($name, $required = false)
    {
        $privateKeys = $this->get('privateKeys');
        $key = array_filter($privateKeys, function (PrivateKey $key) use($name) {
            return $key->getName() === $name;
        });
        $keyCount = count($key);
        if ($keyCount !== 1 && $required) {
            throw new \RuntimeException(sprintf('Attempted to get privateKey by name "%s", found "%d" keys, where only one was expected. Please ' . 'verify that your configuration is correct', $name, $keyCount));
        }
        if (!$keyCount) {
            return null;
        }
        return array_pop($key);
    }