What feature would you like to see?

I would like to be able to set or change the OkHttpClient instance of FirebaseFunctions.
Currently this is not possible because the private field is initialized in the constructor.

This would enable using a shared and preconfigured OkHttpClient instance which could lead to improved I/O performance.

How would you use it?

As of now I only want to configure a custom User-Agent string so that we can distinguish between different clients that execute callable functions in the backend.