Flarum\Locale\PrefixedYamlFileLoader::load PHP Method

    public function load($resource, $locale, $domain = 'messages')
    {
        $catalogue = parent::load($resource['file'], $locale, $domain);
        if (!empty($resource['prefix'])) {
            $messages = $catalogue->all($domain);
            $prefixedKeys = array_map(function ($k) use($resource) {
                return $resource['prefix'] . $k;
            }, array_keys($messages));
            $catalogue->replace(array_combine($prefixedKeys, $messages));
        }
        return $catalogue;
    }