is it somehow supported in gRPC itself or are there any best practices to just allow a single client connection on a gRPC server? Assuming I have a server where multiple, especially interleaved client access doesn't make sense, how can I prevent this from happening? I can also think of some sort of simple self-implemented user management where the client generates a unique ID and registers itself with the server which then blocks all other accesses until the client deregisters again.