如下是示例代码

package demo.pattern.singleton;

import java.lang.reflect.Constructor;
import java.lang.reflect.InvocationTargetException;

public class EnumStarvingSingleton {
    private EnumStarvingSingleton(){}
    public static EnumStarvingSingleton getInstance(){
        return ContainerHolder.HOLDER.instance;
    }
    private enum ContainerHolder{
        HOLDER;
        private EnumStarvingSingleton instance;
        ContainerHolder(){
            instance = new EnumStarvingSingleton();
        }
    }

    public static void main(String[] args) throws NoSuchMethodException, IllegalAccessException, InvocationTargetException, InstantiationException {
        Class<ContainerHolder> clazz = ContainerHolder.class;
        Constructor<ContainerHolder> constructor = clazz.getDeclaredConstructor();
        constructor.setAccessible(true);
        ContainerHolder newInstance = constructor.newInstance();
    }
}

我的问题是：
ContainerHolder枚举类不是有一个无参的构造函数吗？

		ContainerHolder(){
            instance = new EnumStarvingSingleton();
        }

那为什么下面这行代码获取不到对应的构造函数呢？

        Constructor<ContainerHolder> constructor = clazz.getDeclaredConstructor();