Is it possible to change the bootstrap accordion so that clicking on one tab does not hide previously opened ones?

Question

css

Is it possible to change the bootstrap accordion so that clicking on one tab does not hide previously opened ones?

Answer 1

https://itchief.ru/lessons/bootstrap-3/bootstrap-3...
clearly described, willing to answer questions
example (one of the options):

<div class="panel-group" id="accordion11">
  <div class="panel panel-default">
    <div class="panel-heading">
      <h4 class="panel-title">
        <a data-toggle="collapse" data-parent="#accordion11" href="#collapse11">заголовок 1-й панели</a>
      </h4>
    </div>
    <div id="collapse11" class="panel-collapse collapse">
      <div class="panel-body">
контент 1-й панели
 </div>
    </div>
  </div>
  </div>

  <div class="panel-group" id="accordion12">
  <div class="panel panel-default">
    <div class="panel-heading">
      <h4 class="panel-title">
        <a data-toggle="collapse" data-parent="#accordion12" href="#collapse12">заголовок 2-й панели</a>
      </h4>
    </div>
    <div id="collapse12" class="panel-collapse collapse">
      <div class="panel-body">
контент 2-й панели
    </div>
  </div>
  </div>
</div>