class DatePeriod
{
    // Signature 1: can be called with 3 or 4 arguments.
    public function __construct(DateTimeInterface $start, DateInterval $interval, int $recurrences, int $options = 0) {}
 
    // Signature 2: can be called with 3 or 4 arguments.
    public function __construct(DateTimeInterface $start, DateInterval $interval, DateTimeInterface $end, int $options = 0) {}
 
    // Signature 3: can be called with 1 or 2 arguments.
    public function __construct(string $isostr, int $options = 0) {}
}

class DatePeriod
{
    // Signature 1: unchanged behavior, signature 4 will merely merge 1 and 2.
    
    // Signature 2: unchanged behavior, signature 4 will merely merge 1 and 2.

    // Signature 3: deprecated in 8.4, removed in a future (TBD) major version.

    // Signature 4: unchanged behavior, merges signatures 1 and 2 in a future (TBD) major version.
    // From the user's perspective, this is only a documentation update.
    public function __construct(DateTimeInterface $start, DateInterval $interval, DateTimeInterface|int $end, int $options = 0) {} 
 
    // Named constructor: replaces signature 3, added in PHP 8.3
    public static function createFromISO8601String(string $specification, int $options = 0): static {}
}