Leap Year

Implement and test a leap year calculator:

class LeapYearCalculator {
public static boolean isLeapYear(int year) {
// ???
}
}

Assume y is a year, 2008, for example. Then y is a leap year (contains an extra day, February 29) if

y > 1582 // = the year leap years were introduced
y is divisible by 4
but y is not divisible by 100
unless y is divisible by 400

For example, 1900 is not a leap year, but 2000 is a leap year.