private function nextToken($capture_doc_comment = FALSE) {
    $this->iterator->next();
    $capture_doc_comment ? $this->skipHiddenCaptureDocComment() : $this->skipHidden();
    $this->current = $this->iterator->current();
    if ($this->current) {
      $this->currentType = $this->current->getType();
    }
    else {
      $this->currentType = NULL;
    }
  }