当一个类的构造函数被定义为private时如何创建该类的实例

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class Goods{
  private  $Name;
  private $Price;
  private $Color;
  private $type;
  private $goods;
  private function __construct($Name,$Price,$Color,$type){
   $this->Name=$Name;
   $this->Price=$Price;
   $this->Color=$Color;
   $this->type=$type;
   
   
  }
  function  getIstance(){
   if($goods==null)
   $goods=new Goods("面包",3.5,"橙黄","食品");
   return $goods;
  }
  function __destruct(){
   echo "清除价格",$this->Price;
 
  } 
  
}
 Goods::getIstance();
 
 

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