1.
Modify your SimpleCircle class to print "SimpleCircle(<origin>,
<radius>) when sent the printString message. <origin> and
<radius>are to be replaced with the actual values of the origin and
radius instance variables of the SimpleCircle object.
2.
Write SUnit tests for the methods in your SimpleCircle class. Correct any
errors in your SimpleCircle code.
3.
Write SUnit tests for the methods isPrime, divides:, and asLetterGrade created
in assignment 2. Correct any errors you discover in your methods from
assignment 2.