code: public function sayHello()
      {
          $text = $this->getHALLogo();
  
          if ($this->showText) {
              $text .= $this->getHelloDave();
          }
  
          $lines = explode("\n", $text);
  
          $spaces = '';
          if ($this->center) {
              $max_length = 0;
              foreach ($lines as $line) {
                  $max_length = max($max_length, Helper::strlenWithoutDecoration($this->output->getFormatter(), $line));
              }
  
              $numberOfSpaces = floor(($this->screenSize[0] - $max_length) / 2);
              if ($numberOfSpaces > 0) {
                  $spaces = str_repeat(' ', $numberOfSpaces);
              }
          }
  
          foreach ($lines as $line) {
              $this->output->writeln($spaces.$line);
          }
      }
docs: Writes HAL Logo