Leap Years

In this kata you should simply determine, whether a given year is a leap year or not. In case you don't know the rules, here they are:

• Years divisible by 4 are leap years,
• but years divisible by 100 are not leap years,
• but years divisible by 400 are leap years.

Tested years are in range 1600 ≤ year ≤ 4000.