Of the abstraction. The values for getRadius() or getCircumference() in the above mentioned illustration might be saved right, or they may be calculated, it doesn't make any difference towards the caller; the setters could or may not have Negative effects; it won't matter into the caller. See @michael-puckett-ii 's answer https://propertyingurugram.in/luxury-homes-capture-45-of-delhi-ncr-real-estate-sales-gurugram-leads/