如何为sequelize添加Global hooks？
现在只能通过类似下面的代码添加hooks函数
```js
// Method 1 via the .init() method
class User extends Model {}
User.init({
  username: DataTypes.STRING,
  mood: {
    type: DataTypes.ENUM,
    values: ['happy', 'sad', 'neutral']
  }
}, {
  hooks: {
    beforeValidate: (user, options) => {
      user.mood = 'happy';
    },
    afterValidate: (user, options) => {
      user.username = 'Toni';
    }
  },
  sequelize
});

```

我想为sequelize添加Global hooks,就像这样[https://sequelize.org/master/manual/hooks.html](https://sequelize.org/master/manual/hooks.html)
```js
const sequelize = new Sequelize(..., {
  define: {
    hooks: {
      beforeCreate() {
        // Do stuff
      }
    }
  }
});
```
我该在那个地方可以初始化sequelize实例？

