/bootstrap.js"></script>
<script>
var easings = [
  '',
  'linear',
  'ease-in-out',
  'step-middle',
  'steps(4, end)',
];

var keyframeHeight = 50;
var timing = {duration: easings.length * 1000, fill: 'forwards'};

control.animate({height: easings.length * keyframeHeight + 'px'}, timing);

var keyframes = [];
easings.forEach(function (easing, i) {
  var textBlock = document.createElement('div');
  textBlock.textContent = easing.length ? easing : '<default>';
  textBlock.classList.add('block');
  container