.appendChild(textBlock);
  var keyframe = {height: i * keyframeHeight + 'px'};
  if (easing.length) {
    keyframe.easing = easing;
  }
  keyframes.push(keyframe);
});
keyframes.push({height: easings.length * keyframeHeight + 'px'});
target.animate(keyframes, timing);
</script>
