in jekyll/plugins/toc_generator.rb [28:38]
def generate(site)
toc_output = site.config['toc_output'] || 'HelpTOC.json'
toc_content = site.data['toc']
toc_page = TocPage.new(site, site.source, '/', toc_output, toc_content.to_json)
site.pages << toc_page
populate_prev_next(site, toc_content)
end