static public function getFromId($networkId, $field = "name")
    {
        foreach (self::$networkInfos as $name => $spec) {
            if ($spec["id"] !== (int) $networkId) continue;

            if ($field === "name")
               return $name;
            elseif (in_array($field, array_keys($spec)))
                return $spec[$field];
            else
                // Field not recognized
                return null;
        }

        // Network ID not recognized
        return null;
    }