I copied & pasted the example code from readme ```go package dgraph import ( "log" "google.golang.org/grpc" "github.com/dgraph-io/dgo" "github.com/dgraph-io/dgo/protos/api" "context" ) func F() error { conn, err := grpc.Dial("localhost:5080", grpc.WithInsecure()) if err != nil { log.Fatal(err) } defer conn.Close() dgraphClient := dgo.NewDgraphClient(api.NewDgraphClient(conn)) op := &api.Operation{ Schema: `name: string @index(exact) .`, } err = dgraphClient.Alter(context.Background(), op) return err } ``` get ``` rpc error: code = Unimplemented desc = unknown service api.Dgraph ```