File: //lib/ruby/3.0.0/rdoc/generator/template/darkfish/_sidebar_table_of_contents.rhtml
<%- comment = if current.respond_to? :comment_location then
current.comment_location
else
current.comment
end
table = current.parse(comment).table_of_contents
if table.length > 1 then %>
<div class="nav-section">
<h3>Table of Contents</h3>
<ul class="link-list" role="directory">
<%- table.each do |heading| -%>
<li><a href="#<%= heading.label current %>"><%= heading.plain_html %></a>
<%- end -%>
</ul>
</div>
<%- end -%>