old_contents: /* Tabs JS implementation. Borrowed from Skaffold */
  function initTabs() {
    try{
      $('.tab-content').find('.tab-pane').each(function(idx, item) {
        var navTabs = $(this).closest('.code-tabs').find('.nav-tabs'),
            title = escape($(this).attr('title')).replace(/%20/g, ' '),
            os = escape($(this).attr('os') || '');
        navTabs.append('<li class="nav-tab '+os+'"><a href="#" class="nav-tab">'+title+'</a></li>');
      });
  
      $('.code-tabs ul.nav-tabs').each(function() {
        let tabSelector = getTabSelector(this);
        $(this).find('li'+tabSelector).addClass('active');
      });
  
      $('.code-tabs .tab-content').each(function() {
        let tabSelector = getTabSelector(this);
        $(this).find('div'+tabSelector).addClass('active');
      })
  
      $('.nav-tabs a').click(function(e){
        e.preventDefault();
        var tab = $(this).parent(),
            tabIndex = tab.index(),
            tabPanel = $(this).closest('.code-tabs'),
            tabPane = tabPanel.find('.tab-pane').eq(tabIndex);
        tabPanel.find('.active').removeClass('active');
        tab.addClass('active');
        tabPane.addClass('active');
      });
    } catch(e) {
      const elements = document.getElementsByClassName("tab-pane");
      for (let element of elements) {
        element.style.display = "block";
        const title = document.createElement("h3");
        title.innerText = element.title;
        title.classList.add("backup-tab-title");
        element.prepend(title);
      }
    }
  }
  
  const getTabSelector = currElement => {
      let osSelector = '.'+getUserOS();
      let hasMatchingOSTab = $(currElement).find(osSelector).length;
      return hasMatchingOSTab ? osSelector : ':first';
  }
  
  const getUserOS = () => {
      let os = ['Linux', 'Mac', 'Windows'];
      let userAgent = navigator.userAgent;
      for (let currentOS of os) {
        if (userAgent.indexOf(currentOS) !== -1) return currentOS;
      }
      return 'Linux';
  }
  
new_contents: /* Tabs JS implementation. Borrowed from Skaffold */
  function initTabs() {
    try{
      $('.tab-content').children('.tab-pane').each(function(idx, item) {
        var navTabs = $(this).closest('.code-tabs').children('.nav-tabs'),
            title = escape($(this).attr('title')).replace(/%20/g, ' '),
            os = escape($(this).attr('os') || '');
        navTabs.append('<li class="nav-tab '+os+'"><a href="#" class="nav-tab">'+title+'</a></li>');
      });
  
      $('.code-tabs ul.nav-tabs').each(function() {
        let tabSelector = getTabSelector(this);
        $(this).find('li'+tabSelector).addClass('active');
      });
  
      $('.code-tabs .tab-content').each(function() {
        let tabSelector = getTabSelector(this);
        $(this).find('div'+tabSelector).addClass('active');
      })
  
      $('.nav-tabs a').click(function(e){
        e.preventDefault();
        var tab = $(this).parent(),
            tabIndex = tab.index(),
            tabPanel = $(this).closest('.code-tabs'),
            tabPane = tabPanel.find('.tab-content:first').children('.tab-pane').eq(tabIndex);
        tab.siblings().removeClass('active');
        tabPane.siblings().removeClass('active');
        tab.addClass('active');
        tabPane.addClass('active');
      });
    } catch(e) {
      const elements = document.getElementsByClassName("tab-pane");
      for (let element of elements) {
        element.style.display = "block";
        const title = document.createElement("h3");
        title.innerText = element.title;
        title.classList.add("backup-tab-title");
        element.prepend(title);
      }
    }
  }
  
  const getTabSelector = currElement => {
      let osSelector = '.'+getUserOS();
      let hasMatchingOSTab = $(currElement).find(osSelector).length;
      return hasMatchingOSTab ? osSelector : ':first';
  }
  
  const getUserOS = () => {
      let os = ['Linux', 'Mac', 'Windows'];
      let userAgent = navigator.userAgent;
      for (let currentOS of os) {
        if (userAgent.indexOf(currentOS) !== -1) return currentOS;
      }
      return 'Linux';
  }
  
subject: support nested tabs