如何使用node-restful插入子文档？

const restful = require('node-restful');

const mongoose = restful.mongoose;

const childSchema = new mongoose.Schema({
  name: String,
  age: Number
});

const ChildModel = mongoose.model('Child', childSchema);

const parentSchema = new mongoose.Schema({
  name: String,
  child: [childSchema] // 子文档字段
});

const ParentModel = restful.model('Parent', parentSchema);

ParentModel.methods(['post']); // 定义只允许POST请求
ParentModel.register(app, '/parents'); // 注册路由

// POST /parents
// 请求体中包含子文档数据
// {
//   "name": "Parent",
//   "child": [
//     {
//       "name": "Child 1",
//       "age": 10
//     },
//     {
//       "name": "Child 2",
//       "age": 12
//     }
//   ]
// }