Bootstrap Collapse - Expand All

I've implemented Bootstrap 3 Collapse. The client wants all of the target blocks to expand when any one of the heading links is clicked. I have tried to implement a modified version of this answer, but can't get it working.

How can I get all target blocks to expand/collapse when any one of them is clicked?

This is the markup:

<div class="panel-group" id="accordion">
    <div class="panel panel-default">
        <div class="panel-heading">
            <h6 class="panel-title"><a data-toggle="collapse" data-parent="#accordion" href="#collapse{entry_id}">{title}</a></h6>
        </div>
    </div>
    <div id="collapse{entry_id}" class="panel-collapse collapse">
      <div class="panel-body">
        {technology_body}
      </div>
   </div>
</div>

And this is the JS I have attempted:

$('#accordion').on('click', function() {
    if($('.collapse:not(.in)')) {
         $.collapse("toggle");
    }
});