ServiceNow Batch API - An example of using this API with PowerShell

The official documentation only gave a CURL example https://developer.servicenow.com/dev.do#!/reference/api/tokyo/rest/batch-api

This blog entry in the community is fairly good and tried to add to the doco and make it more useful. https://www.servicenow.com/community/now-platform-articles/an-introduction-to-the-batch-rest-api-endpoint-api-now-batch/ta-p/2317136

What I wanted to see was a working example that I could use, preferably in PowerShell. The PowerShell here is based on the sample for the table API supplied in the API Explorer.

I managed to get it working after a bit and thought I might place it here for anyone to use.

Enjoy!