如何将在mongoose上创建的对象推送到另一个模式中

const mongoose = require('mongoose');

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

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

const newUser = new User({
  name: 'John',
  age: 25
});

newUser.save()
  .then(() => {
    console.log('User saved successfully.');
  })
  .catch((error) => {
    console.error('Error saving user:', error);
  });

const anotherSchema = new mongoose.Schema({
  user: {
    type: mongoose.Schema.Types.ObjectId,
    ref: 'User'
  }
});

const AnotherModel = mongoose.model('AnotherModel', anotherSchema);

const anotherObject = new AnotherModel({
  user: newUser._id
});

anotherObject.save()
  .then(() => {
    console.log('Object saved successfully.');
  })
  .catch((error) => {
    console.error('Error saving object:', error);
  });