如何在mongoose模式中添加required in对象或对象数组？

const mongoose = require('mongoose');
const Schema = mongoose.Schema;

const addressSchema = new Schema({
  street: {
    type: String,
    required: true
  },
  city: {
    type: String,
    required: true
  },
  // 其他地址字段...
});

const userSchema = new Schema({
  name: String,
  address: addressSchema,
  // 其他用户字段...
});

const User = mongoose.model('User', userSchema);

const mongoose = require('mongoose');
const Schema = mongoose.Schema;

const itemSchema = new Schema({
  name: {
    type: String,
    required: true
  },
  quantity: {
    type: Number,
    required: true
  }
  // 其他商品字段...
});

const orderSchema = new Schema({
  items: [itemSchema],
  // 其他订单字段...
});

const Order = mongoose.model('Order', orderSchema);