TypeScript doesn't know how to generate a `class` definition when we use the `sequelize.define` method to define a Model. Therefore, we need to do some manual work and declare an interface and a type, and eventually cast the result of `.define` to the _static_ type.
In Sequelize versions before v5, the default way of defining a model involved using `sequelize.define`. It's still possible to define models with that, and you can also add typings to these models using interfaces.
```ts
// We need to declare an interface for our model that is basically what our class would be
interfaceMyModelextendsModel{
// We recommend you declare an interface for the attributes, for stricter typechecking
If you're comfortable with somewhat less strict typing for the attributes on a model, you can save some code by defining the Instance to just extend `Model` without any attributes in the generic types.
// Need to declare the static model so `findOne` etc. use correct types.
* This method is not aware of eager loaded associations. In other words, if some other model instance (child) was eager loaded with this instance (parent), and you change something in the child, calling `save()` will simply ignore the change that happened on the child.
