<div class="panel {{panelClass || 'panel-default'}}">
  <div class="panel-heading" ng-keypress="toggleOpen($event)">
    <h4 class="panel-title">
      <a href tabindex="0" class="accordion-toggle" ng-click="toggleOpen()" accordion-transclude="heading"><span ng-class="{'text-muted': isDisabled}">{{heading}}</span></a>
    </h4>
  </div>
  <div class="panel-collapse collapse" collapse="!isOpen">
	  <div class="panel-body" ng-transclude></div>
  </div>
</div>
