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222: Mainline

You may wish to use getters to provide access to derived attributes that exist only in the sense that their values can be computed from instance variables that do exist. For example, you can create fGrams, which seems to refer to the contents of an fGrams instance variable, but which actually refers to the contents of the fCalories instance variable:

Vegetable method definition • instance 
fGrams  
  ^ fCalories / 9 

From the behavior perspective, fGrams provides the answers you want, and you do not need to concern yourself with how those answers are produced.