IModelChangeListener (Demo 2.1.1 API)

```
public interface IModelChangeListener
```
Defines a listener to be invoked when the model changes. This interface is intended to be used when the UI includes elements that depend on a model. If the user takes action to change the model, those elements may require modification.
Note: Implementations of this interface are discouraged to not maintain a reference to the model as a member element. Because models may contain a very large amount of memory, the application should be designed so that only one model is loaded at a time. The recommended approach is for the listener to maintain a reference to the DataViewingPanel and use it to obtain a reference to the model as a local variable within the scope of methods that need it.

All Methods Instance Methods Abstract Methods
Modifier and Type	Method and Description
`void`	`modelAdded(IModel model)` Invoked whenever a model is added.
`void`	`modelRemoved()` Invoked whenever a model is removed.

Interface IModelChangeListener