public static final function getConfig($key = null)
{
$calledClass = get_called_class();
// Load config
if (!isset(self::$loadedConfigSet[$calledClass]) || null === self::$loadedConfigSet[$calledClass]) {
self::$loadedConfigSet[$calledClass] = array_merge(self::$configDefault, static::loadConfig());
}
// Get config property
return null === $key ? self::$loadedConfigSet[$calledClass] : self::$loadedConfigSet[$calledClass][$key];
}