On page 97 (v. Beta 4): The book jumps to…Our server now authorizes its requests!
However, the reader is not ready yet b/c they need to add the wiring to server_test.go
authorizer := auth.New(config.ACLModelFile, config.ACLPolicyFile) // <--- here
cfg = &Config{
CommitLog: clog,
Authorizer: authorizer, // <--- here
}