app/views/trestle/application/_layout.html.erb
<%= render "header", hide_breadcrumbs: local_assigns.fetch(:hide_breadcrumbs, false) if local_assigns.fetch(:header, true) %>
<div class="main-content-area">
<%= render "trestle/flash/flash" %>
<%= render "utilities" %>
<%= render "tabs" %>
<% if local_assigns.fetch(:wrapper, true) %>
<%= container do |c| %>
<%= yield %>
<% c.sidebar do %>
<%= content_for(:sidebar) %>
<% end if content_for?(:sidebar) %>
<% end %>
<% else %>
<%= yield %>
<% end %>
</div>