bootstrap-2-2-8.html.twig in Bootstrap Layouts 8.3

<div {{ attributes.addClass('row') }} >
  {{ title_suffix.contextual_links }}
  {% if content.sidebar_left %}
  <div class="col-sm-2">
    {{ content.sidebar_left }}
  </div>
  {% endif %}
  {% if content.main %}
  <div class="col-sm-2">
    {{ content.main }}
  </div>
  {% endif %}

  {% if content.sidebar_right %}
  <div class="col-sm-8">
    {{ content.sidebar_right }}
  </div>
  {% endif %}
</div>