Dynamic References import all attributes from the reference object to the specified object.
    It works similar to the `#ref` however allows for customization of properties and attributes.
    The dynamic reference uses a `$` instead of `#` for the `ref` attribute.


    Define a default object which be our base structure.
    In this case it is a response, which will contain a variable `data` property.
    We are also showing how it is possible to extend Definitions on sub Schemas by extending the 'ExampleDefinition'.

    Then you can extend the response in this example POST request by using the '$' ref.
    As you can see `ref="$/responses/Json` is telling it to extend the base `Json` response.
    We follow the reference with a `Schema` layout which specifies that the `data` property will actually be a `Product`.