code: public function isPartialCodeMultiline($start, $end)
      {
          for ($i = $start; $i <= $end; ++$i) {
              if (false !== strpos($this[$i]->getContent(), "\n")) {
                  return true;
              }
          }
  
          return false;
      }
docs: @param int $start start index
  @param int $end   end index
  
  @return bool