public function calcAge(DateTime $birthDate, DateTime $refDate = null) {
        return DateTimeRenderer::renderAge($birthDate, $refDate);
    }
public function calcAge(DateTime $birthDate, DateTime $refDate = null) {
        return DateTimeRenderer::renderAge($birthDate, $refDate);
    }
public function calcAge ( DateTime $ birthDate , DateTime $ refDate = null ) { return DateTimeRenderer :: renderAge ( $ birthDate , $ refDate ) ; }
Calculates an age.

@param DateTime $birthDate The birth date.
@param DateTime|null $refDate The reference date.
@return int Returns teh age.
@throws Exception Throws an exception if an error occurs.
Calculates an age .