First off, there is no version 1.0.13. 
For this latest release, I have added one handy new function getParentId(). This function uses the child message “InReplyTo” field to locate the parent message with the same corresponding “InternetMessageId” field. If found, you will get the Id of that parent message. If not found, you will get NULL.
As per usual, to get the latest you can link to the CDN: https://cdn.jsdelivr.net/gh/davecra/easyEws/easyEws.js
Or you can access it from NPM via this command:
npm -install easyewsNOTE: I was informed that I had forgot to update NPM to v1.0.12 per the last release. So I have fixed that and have updated this build on NPM.