VisualAge can help save you time and get you started by generating certain default scripts.
In the Public Interface Editor:
Notice that asResultString, finishTime, finishTime:, number, and number: are listed on the top-right and the following class definition is displayed in the text area:
AbtAppBldrPart subclass: #Runner instanceVariableNames: 'number finishTime runnerAsResultString' classVariableNames: '' poolDictionaries: ''
Notice that these are all of the selectors and attribute data types you just generated.
Also notice that Runner is a subclass of AbtAppBldrPart. All nonvisual part classes are created as a subclass of AbtAppBldrPart so that they automatically inherit all of the properties and behaviors needed for VisualAge to recognize them and keep them functioning as parts.