code: protected void defaultProcess(Doc doc, boolean fixLeadingSpaces) {
          try {
              StringBuilder buf = new StringBuilder();
              buf.append(getOptions().toHtml(doc.commentText(), fixLeadingSpaces));
              buf.append('\n');
              for ( Tag tag : doc.tags() ) {
                  processTag(tag, buf);
                  buf.append('\n');
              }
              doc.setRawCommentText(buf.toString());
          }
          catch ( final ParserRuntimeException e ) {
              if ( doc instanceof RootDoc ) {
                  printError(new SourcePosition() {
                      @Override
                      public File file() {
                          return options.getOverviewFile();
                      }
                      @Override
                      public int line() {
                          return 0;
                      }
                      @Override
                      public int column() {
                          return 0;
                      }
                  }, e.getMessage());
              }
              else {
                  printError(doc.position(), e.getMessage());
              }
          }
      }
docs: Default processing of any documentation node.
  
  @param doc              The documentation.
  @param fixLeadingSpaces `true` if leading spaces should be fixed.
  
  @see Options#toHtml(String, boolean)