panel.pt

<div
    tal:define="title field.title;
                widgets field.my_widgets;"
    class="panel">
    <div tal:condition="title != 'No Title'" class="panel-heading bg-info">
        <h2 class="panel-title text-center">${title}</h2>
    </div>
    <div class="panel-body">
        <div tal:replace="structure widgets"/>
    </div>
</div>