如何在mongoose中使用自定义类型？

I have the following schema:

我有以下架构:

var Location = new Schema({
    x: {
        type: String
    },
    y: {
        type: String
    }
 },{
    _id: false
 });

 var AppSchema = new Schema({
    link: {
        type: String
    },
    location: {
        type: Location
    }
})
var Lo