<%def name="panel(title='', category='default', class_='')">
    <div class="panel panel-${category} ${class_}">
    %if title or hasattr(caller, 'title'):
      <div class="panel-heading">
        <h3 class="panel-title">
        %if title:
        ${title}
        %else:
        ${caller.title()}
        %endif
        </h3>
      </div>
    %endif
      <div class="panel-body">
        ${caller.body()}
      </div>
    </div>
</%def>