File-function context/flow/global missing

I'm using the file-function node and I'm having issues accessing data stored in context/flow/global stores
When I execute the following within the file:
console.log(flow.keys());
I get the following error:
[warn] [file function:Decoder] ReferenceError: flow is not defined

Any ideas on how I can access these variable stores?

That node hasnt been updated for over two years so has fallen far behind the core function node.

I see an issue has already been raised, but gone unanswered: https://github.com/emiloberg/node-red-contrib-file-function/issues/3