<?php
  
  /**
   * This file is part of the Carbon package.
   *
   * (c) Brian Nesbitt <brian@nesbot.com>
   *
   * For the full copyright and license information, please view the LICENSE
   * file that was distributed with this source code.
   */
  
  namespace Carbon;
  
  class CarbonPeriodImmutable extends CarbonPeriod
  {
      /**
       * Default date class of iteration items.
       *
       * @var string
       */
      protected const DEFAULT_DATE_CLASS = CarbonImmutable::class;
  
      /**
       * Date class of iteration items.
       *
       * @var string
       */
      protected $dateClass = CarbonImmutable::class;
  
      /**
       * Prepare the instance to be set (self if mutable to be mutated,
       * copy if immutable to generate a new instance).
       *
       * @return static
       */
      protected function copyIfImmutable()
      {
          return $this->constructed ? clone $this : $this;
      }
  }