code: public function isDryRun()
      {
          if (null === $this->isDryRun) {
              if ($this->isStdIn()) {
                  // Can't write to STDIN
                  $this->isDryRun = true;
              } else {
                  $this->isDryRun = $this->options['dry-run'];
              }
          }
  
          return $this->isDryRun;
      }
docs: Returns dry-run flag.
  
  @return bool