Of this abstraction. The values for getRadius() or getCircumference() in the above mentioned example may be saved directly, or they may be calculated, it doesn't issue to your caller; the setters could or won't have Unwanted effects; it would not make a difference to the caller. See @michael-puckett-ii 's reply https://propertyingurugram.in/sales-of-luxury-homes-go-up-in-gurugram/