code: protected function compile()
  	{
  		System::loadLanguageFile('tl_maintenance');
  
  		$this->Template->content = '';
  		$this->Template->href = $this->getReferer(true);
  		$this->Template->title = StringUtil::specialchars($GLOBALS['TL_LANG']['MSC']['backBTTitle']);
  		$this->Template->button = $GLOBALS['TL_LANG']['MSC']['backBT'];
  
  		foreach ($GLOBALS['TL_MAINTENANCE'] as $callback)
  		{
  			$this->import($callback);
  
  			if (!$this->$callback instanceof \executable)
  			{
  				throw new \Exception("$callback is not an executable class");
  			}
  
  			$buffer = $this->$callback->run();
  
  			if ($this->$callback->isActive())
  			{
  				$this->Template->content = $buffer;
  				break;
  			}
  			else
  			{
  				$this->Template->content .= $buffer;
  			}
  		}
  	}
docs: Generate the module
  
  @throws \Exception