Add the GRPC unimplemented method handler class

lb.go

@@ -190,6 +190,8 @@ type Loadbalancer struct {
 
 	mx    sync.Mutex
 	nodes map[string]*node
+
+	lbpb.UnimplementedLoadBalancerServer
 }
 
 // New returns a new Loadbalancer with the given utilization limits