valueForId(value) {
    return value;
  }
Used to customize how a model's primary key value is formatted in your JSON payload.

    By default, the primary key is a string

    ```
    GET /authors/1

    {
      author: {
        id: '1',
        firstName: 'Link',
        lastName: 'The WoodElf'
      }
    }
    ```

    If your API expects a integers, you could write the following:

    ```js
    // serializers/application.js
    export default Serializer.extend({
      valueForId(value) {
        return parseInt(value);
      }
    });
    ```

    Now the response would look like:

    ```
    {
      author: {
        authorId: 1,
        firstName: 'Link',
        lastName: 'The WoodElf'
      }
    }
    ```

    @method valueForId
    @param value
    @public