code: protected function createConfigurationDefinition()
      {
          return new FixerConfigurationResolverRootless('replacements', [
              (new FixerOptionBuilder('replacements', 'Mapping between replaced functions with the new ones.'))
                  ->setAllowedTypes(['array'])
                  ->setAllowedValues([static function ($value) {
                      foreach ($value as $functionName => $replacement) {
                          if (!\array_key_exists($functionName, self::$argumentCounts)) {
                              throw new InvalidOptionsException(sprintf(
                                  'Function "%s" is not handled by the fixer.',
                                  $functionName
                              ));
                          }
  
                          if (!\is_string($replacement)) {
                              throw new InvalidOptionsException(sprintf(
                                  'Replacement for function "%s" must be a string, "%s" given.',
                                  $functionName,
                                  \is_object($replacement) ? \get_class($replacement) : \gettype($replacement)
                              ));
                          }
                      }
  
                      return true;
                  }])
                  ->setDefault([
                      'getrandmax' => 'mt_getrandmax',
                      'rand' => 'mt_rand',
                      'srand' => 'mt_srand',
                  ])
                  ->getOption(),
          ], $this->getName());
      }
docs: {@inheritdoc}