PayPal\Auth\Oauth\OAuthRequest::get_signature_base_string PHP Метод

    public function get_signature_base_string()
    {
        $parts = array($this->get_normalized_http_method(), $this->get_normalized_http_url(), $this->get_signable_parameters());
        $parts = OAuthUtil::urlencode_rfc3986($parts);
        return implode('&', $parts);
    }