Facade对应对象 全局唯一还是时刻变化

Illuminate\Support\Facades\Facade;
public static function __callStatic($method, $args)
{
  $instance = static::getFacadeRoot();
 if (! $instance) {
  throw new RuntimeException('A facade root has not been set.');
  }
  return $instance->$method(...$args);
}Copy

    protected static function resolveFacadeInstance($name)
    {
        if (is_object($name)) {
            return $name;
        }
        if (isset(static::$resolvedInstance[$name])) {
            return static::$resolvedInstance[$name];
        }

        if (static::$app) {
            return static::$resolvedInstance[$name] = static::$app[$name];
        }
    }Copy

    protected static function resolveFacadeInstance($name)
    {
         return  static::$app[$name];
    }Copy