isLeapYear static method
Checks if the given year is a leap year.
Returns true if the year is a leap year, false otherwise.
Implementation
static bool isLeapYear({required int year}) =>
// A year is a leap year if it is divisible by 4
year % leapYearModulo4 == 0
// A year is not a leap year if it is divisible by 100
&&
(year % leapYearModulo100 != 0
// unless it is also divisible by 400
||
year % leapYearModulo400 == 0);