private function ignoreComment()
 {
     start:
     if (!$this->stream->currentAscii()->isVerticalSpace() && !$this->stream->isEnd()) {
         $this->stream->next();
         goto start;
     }
 }
 /**
  * @param StringStream $stream
  * @return string
  */
 private function getFullString(StringStream $stream) : string
 {
     $stream->start();
     $string = '';
     do {
         $string .= $stream->current();
         $stream->next();
     } while (!$stream->isEnd());
     return $string;
 }