@Override
    public String toString()
    {
        StringBuilder sb = new StringBuilder();
        sb.append("<tr");
        //boolean rowWithNesting = hasNestedTable();
        if ( isHidden() )
            sb.append(" class=\"hidden\"" );
        //else if ( rowWithNesting )
        //    sb.append(" class=\"nested\"" );
        if ( nested )
            sb.append("><td class=\"siglumhidden\">");
        else
            sb.append("><td class=\"siglumleft\">");
        // write siglum
        String versionsString = Utils.bitSetToString(sigla,groups,versions);
        sb.append( versionsString );
        sb.append("</td>");
        for ( int i=0;i<cells.size();i++ )
        {
            FragList fl = cells.get(i);
            if ( fl.merged && fl.isBase )
                fl.setID( id++ );
            sb.append( fl.toString() );
        }
        sb.append("</tr>");
        return sb.toString();
    }