{% if events %}
<div class="tree-controls">
  <button type="button" class="tree-expand-all">Expand all</button>
  <button type="button" class="tree-collapse-all">Collapse all</button>
</div>
<ol class="tree">
  {% for ev in events %}
    {% include "sessions/_event_row.html" %}
  {% endfor %}
</ol>
{% else %}
<p class="empty">No events in this session.</p>
{% endif %}