public function getAuthenticationUrl($state = null, $forceVerify = false)
    {
        return implode('', [
            sprintf('%soauth2/authorize', $this->baseUri),
            '?response_type=code',
            sprintf('&client_id=%s', $this->getClientId()),
            sprintf('&redirect_uri=%s', $this->getRedirectUri()),
            sprintf('&scope=%s', implode('+', $this->getScope())),
            sprintf('&state=%s', $state),
            sprintf('&force_verify=%s', $forceVerify ? 'true' : 'false'),
        ]);
    }