`cln_grpc`: How to use default behavior of `exposeprivatechannels`?

[ErikDeSmedt]

Context

The invoice-method in the JSON-rpc has a exposeprivatechannels-field. If this field is not specified Core Lightning will only include private channels in the invoice if no public channels are available.

I'd like to get the same behavior using cln_grpc. In this case the exposeprivatechannels-field which expects a vector of short-channel-id's. If the vector is empty, the invoice will not contain any private channels.

[daywalker90]

I don't believe the behaviour is different using cln-(g)rpc. I think it's just a bit random or depending on your test setup if the invoice contains any channels.