Reference for the HA global in Node-RED function nodes?

I can’t seem to find documentation for the HA global that is importable in function nodes. I’ve seen this pattern and variations on code that uses it in forum postings:

const globalHomeAssistant = global.get('homeassistant');
const ha = globalHomeAssistant.homeAssistant;

Is there a comprehensive reference anywhere for what you can do with ha here?