code: function toggleCollapseButton(event) {
      var button = event.target.parentNode;
      var content = button.parentNode.nextSibling;
      var inner = content.children[0];
  
      if (button.className.indexOf('collapse-button') === -1) {
        // Clicked without hitting the right element?
        return;
      }
  
      if (content.style.maxHeight && content.style.maxHeight !== '0px') {
          // Currently showing, so let's hide it
          button.className = 'collapse-button';
          content.style.maxHeight = '0px';
      } else {
          // Currently hidden, so let's show it
          button.className = 'collapse-button show';
          content.style.maxHeight = inner.offsetHeight + 12 + 'px';
      }
  }
docs: /*
  Collapse or show a request/response example.