function isEmptyNode(node){
  if(!node.childNodes || node.childNodes.length === 0) {
    return true;
  } else {
    return false;
  }
}
Check if the node is empty. Some plist file has such node:
<key />
this node shoud be ignored.

@see https://github.com/TooTallNate/plist.js/issues/66
@param {Element} node
@returns {Boolean}
@api private