Your task is to implement the method `isLeap` in the class `LeapYear`.

The method `isLeap` determines if a given year is a leap year or not.

A leap year is a year that is divisible by `4` except if the year is divisible by `100` then the year is not a leap year except if the year is divisible by `400` then the year is a leap year.

To support you with implementing the method there are unit tests in `LeapYearTest`. The unit tests are disabled at the start. To use them you have to enable them.

To perform this exercise you need a JDK 8 and Maven 3.3.x.