isSameWeek method
Whether this date is in the same week as other
Implementation
bool isSameWeek(DateTime other) {
final thisMonday = subtract(Duration(days: weekday - 1));
final otherMonday = other.subtract(Duration(days: other.weekday - 1));
return DateTime(thisMonday.year, thisMonday.month, thisMonday.day) ==
DateTime(otherMonday.year, otherMonday.month, otherMonday.day);
}