protected function loadCredentials()
    {
        $instance = $this->getInstance();
        if ($instance && $instance->exists()) {

            $props = $instance->getPropertiesValues([
                $this->getProperty(self::PROPERTY_LOGIN),
                $this->getProperty(self::PROPERTY_PASSWORD)
            ]);

            $data = [
                self::PROPERTY_LOGIN => (string)current($props[self::PROPERTY_LOGIN]),
                self::PROPERTY_PASSWORD => (string)current($props[self::PROPERTY_PASSWORD]),
            ];
        } else {
            $data = [
                self::PROPERTY_LOGIN => '',
                self::PROPERTY_PASSWORD => '',
            ];
        }

        return $data;
    }