public function getThemeConfig($theme)
    {
        $themesConfig = $this->getThemesConfig();

        if (!empty($themesConfig[$theme])) {
            return $themesConfig[$theme];
        } elseif (!empty($themesConfig['generic'])) {
            return $themesConfig['generic'];
        }

        throw new RuntimeException(
            'No theme config found for ' . $theme
            . ' and no default theme found'
        );
    }