PHP DateTimeImmutable class

class DateTimeImmutable implements DateTimeImmutableInterface {
  
  //Inherited constants
  const string DateTimeInterface::ATOM = "Y-m-d\TH:i:sP";
  const string DateTimeInterface::COOKIE = "l, d-M-Y H:i:s T";
  const string DateTimeInterface::ISO8601 = "Y-m-d\TH:i:sO";
  const string DateTimeInterface::RFC822 = "D, d M y H:i:s O";
  const string DateTimeInterface::RFC850 = "l, d-M-y H:i:s T";
  const string DateTimeInterface::RFC1036 = "D, d M y H:i:s O";
  const string DateTimeInterface::RFC1123 = "D, d M Y H:i:s O";
  const string DateTimeInterface::RFC7231 = "D, d M Y H:i:s \G\M\T";
  const string DateTimeInterface::RFC2822 = "D, d M Y H:i:s O";
  const string DateTimeInterface::RFC3339 = "Y-m-d\TH:i:sP";
  const string DateTimeInterface::RFC3339_EXTENDED = "Y-m-d\TH:i:s.vP";
  const string DateTimeInterface::RSS = "D, d M Y H:i:s O";
  const string DateTimeInterface::W3C = "Y-m-d\TH:i:sP";
  
  //Methods
  public __construct(string $datetime = "now", ?DateTimeZone $timezone = null)
  public add(DateInterval $interval): DateTimeImmutable
  public static createFromFormat(string $format, string $datetime, 
                       ?DateTimeZone $timezone = null): DateTimeImmutable|false
  public static createFromInterface(DateTimeInterface $object): DateTimeImmutable
  public static createFromMutable(DateTime $object): DateTimeImmutable
  public static getLastErrors(): array|false
  public modify(string $modifier): DateTimeImmutable|false
  public static __set_state(array $array): DateTimeImmutable
  public setDate(int $year, int $month, int $day): DateTimeImmutable
  public setISODate(int $year, int $week, int $dayOfWeek = 1): DateTimeImmutable
  public setTime(int $hour, int $minute, int $second = 0, 
                 int $microsecond = 0): DateTimeImmutable
  public setTimestamp(int $timestamp): DateTimeImmutable
  public setTimezone(DateTimeZone $timezone): DateTimeImmutable
  public sub(DateInterval $interval): DateTimeImmutable
  public diff(DateTimeInterface $targetObject, 
              bool $absolute = false): DateInterval
  public format(string $format): string
  public getOffset(): int
  public getTimestamp(): int
  public getTimezone(): DateTimeZone|false
  public __wakeup(): void
}