fkooman\OAuth\Client\ClientConfig::setClientId PHP Method

    public function setClientId($clientId)
    {
        if (!is_string($clientId) || 0 >= strlen($clientId)) {
            throw new ClientConfigException('client_id must be a non-empty string');
        }
        $this->validateUserPass($clientId);
        $this->clientId = $clientId;
    }