code: function isFlippable(node, prevNode) {
    if (node.type == 'comment') {
      return false;
    }
  
    if (prevNode && prevNode.type == 'comment') {
      return !RE_NOFLIP.test(prevNode.comment);
    }
  
    return true;
  }
docs: Return whether the given `node` is flippable.
  
  @param {Object} node
  @param {Object} prevNode used for @noflip detection
  @returns {Boolean}