code: public function run(InputInterface $input, OutputInterface $output)
      {
          $this->returnCode = static::RETURN_SUCCESS;
          $this->doPreRun($input, $output);
  
          if (!$this->executeDependencies($input, $output)) {
              // Failed to run dependencies.
              $this->returnCode = static::RETURN_ERROR;
          } else {
              // Execute task.
              $this->returnCode = (int) $this->execute($input, $output);
          }
  
          $this->doPostRun($input, $output, $this->returnCode);
  
          return $this->returnCode;
      }
docs: Run task.
  
  @param InputInterface  $input
  Input.
  @param OutputInterface $output
  Output.
  
  @return int $code
  Return code.