A developer has implemented a class that calculates if a given date is a leap year. The definition

for the leap year is given:

Every year that is exactly divisible by four is a leap year, except for years that are exactly

divisible by 100, but these centurial years are leap years if they are exactly divisible by 400.

- divisible by 4

- but not by 100

- years divisible by 400 are leap anyway

You have already thought about it and started with the first test class; the test class looks like

(pseudo JavaScript used here):

// LeapYear.spec.js

describe('Leap year calculator', () => {

it('should consider 1996 as leap', () => {

expect(LeapYear.isLeap(1996)).toBe(true);

});

});

What would now be your next step to proceed as efficient as possible, to validate the correctness

of the class above?