A little confused about the testing functionality. I have SpiceDB running locally with docker and I want persistence for a full local setup. In addition, I want to be able to run unit tests locally using ephemeral data. Can I do this with one SpiceDB container? Or do I need two? Also, it mentions that I can pass a unique token per test in the header. I'm assuming that means that I can't set a SPICEDB_GRPC_PRESHARED_KEY on my server or I need it to be running in test mode... Are there any examples for the Go client that have this set up and running?