Using nonvisual parts
In this section, you learn how to use VA Smalltalk nonvisual parts. We will extend the 
RoadRaceView visual part created in 
Creating reusable parts to make use of these additional VA Smalltalk features. 
The following nonvisual parts are grouped in the Models category of the parts palette: 
   Models Category
Models Category   Ordered Collection
     Ordered Collection Provides a part that contains an ordered group of related objects 
 Object Factory
     Object Factory Provides a part that can dynamically create new instances of a specified part 
 Variable
     Variable Provides a part whose particular instance can vary with time 
 View Wrapper
     View Wrapper Provides a part in this visual part that represents another visual part. 
Last modified date: 06/11/2018