520: Mainline

To enable reporting, you first modify the RabbitApplication class and the initialize method to include and initialize two additional instance variables.

The month variable is to keep track of the current month in the simulation; the history variable is to keep track of the number of rabbits after each month has passed, starting with month 0. Key changes are marked by change bars, .

RabbitApplication class definition
Object subclass: #RabbitApplication
  instanceVariableNames: 'rabbits month history'        
  classVariableNames: ''
  poolDictionaries: ''
RabbitApplication method definition • instance
initialize
  month := 0.                                           
  history := OrderedCollection new.                     
  rabbits := SortedCollection 
             sortBlock: 
             [:x :y | x deliveryMonth < y deliveryMonth]. 
  rabbits add: (Rabbit new deliveryMonth: 2)