isLeapYear assignment

Every year that is exactly divisible by four is a leap year, except for years that are exactly divisible by 100; the centurial years that are exactly divisible by 400 are still leap years. For example, the year 1900 was not a leap year; the year 2000 was a leap year

Is leap year runner skeleton

 Call return value
 isLeapYear(100)  false
 isLeapYear(4)  true
 isLeapYear(104)  true
 isLeapYear(400)  true
 isLeapYear(800)  true
 isLeapYear(5)  false
 isLeapYear(803)  false