无法使用es6类打印方法

Question

为什么下面的代码在记录showInstall

时不会产生输出

class crud_actions {
    constuctor(second){
        this.allitems_colection = 'main',
        this.allitems_example = second
    }
    listall() {   return  this.allitems_example;    }   
}

var test = new crud_actions('solo');
var showinstall = test.listall();

console.log(showinstall);