src/Kernel/Facade.php
protected static function resolveInstance($facadeName)
    {
        if (is_object($facadeName)) {
            return $facadeName;
        }

        if (isset(static::$resolvedInstance[$facadeName])) {
            return static::$resolvedInstance[$facadeName];
        }

        return static::$resolvedInstance[$facadeName] = static::$app->get($facadeName);
    }
protected static function resolveInstance($facadeName)
    {
        if (is_object($facadeName)) {
            return $facadeName;
        }

        if (isset(static::$resolvedInstance[$facadeName])) {
            return static::$resolvedInstance[$facadeName];
        }

        return static::$resolvedInstance[$facadeName] = static::$app->get($facadeName);
    }
Resolved Instance

@param string $facadeName
@return string