docs: function _flush(rootNode) {
    const animatedStyles = new Set();
    function findAnimatedStyles(node) {
      if (typeof node.update === 'function') {
        animatedStyles.add(node);
      } else {
        node.__getChildren().forEach(findAnimatedStyles);
      }
    }
    findAnimatedStyles(rootNode);
    animatedStyles.forEach(animatedStyle => animatedStyle.update());
  }