LocalDate constructor
Constructs a LocalDate from individual parts.
The year uses ISO 8601, or astronomical year numbering and may be zero or negative. When negative, year equates to year - 1 BCE. Throws an exception if month or day is invalid.
Throws an exception if the date would be invalid.
Implementation
LocalDate([this.year = 0, this.month = 1, this.day = 1]) {
_validate();
}