code: public Tag[] firstSentenceTags() {
          if (firstSentence == null) {
              //Parse all sentences first to avoid duplicate warnings.
              inlineTags();
              try {
                  docenv().setSilent(true);
                  firstSentence = Comment.firstSentenceTags(holder, text);
              } finally {
                  docenv().setSilent(false);
              }
          }
          return firstSentence;
      }
docs: Return array of tags for the first sentence in the doc comment text.