code: public function handleComment(Comment $comment)
      {
          if ($this->isCommentMode) {
              $this->formatChildNodes($comment);
              return;
          }
          
          $this->isCommentMode = true;
          $prefix = $this->escapeEndComment($comment->getPrefix());
          $suffix = $this->escapeEndComment($comment->getSuffix());
          $this->result .= $this->indent() . "<!--{$prefix}";
          if ($this->isIndentMode) {
              if ($this->checkBreakModeInComment($comment)) {
                  $breakCode = $this->breakCode();
                  $this->result .= $breakCode;
                  $this->formatChildNodes($comment);
                  $this->result .= $breakCode;
                  $this->result .= $this->indent();
              } else {
                  $this->isIndentMode = false;
                  $this->formatChildNodes($comment);
                  $this->isIndentMode = true;
              }
          } else {
              $this->formatChildNodes($comment);
          }
          $this->result .= "{$suffix}-->";
          $this->isCommentMode = false;
      }
docs: コメントノードを読み込みます.
  @param Comment $comment