add reflection so that you can use it to get definition of services

reflection/server_reflection_test.go

@@ -0,0 +1,28 @@
+package reflection
+
+import (
+	"context"
+	"testing"
+
+	"github.com/kr/pretty"
+
+	testutils "github.com/smallnest/rpcx/_testutils"
+)
+
+type PBArith int
+
+func (t *PBArith) Mul(ctx context.Context, args *testutils.ProtoArgs, reply *testutils.ProtoReply) error {
+	reply.C = args.A * args.B
+	return nil
+}
+
+func TestReflection_Register(t *testing.T) {
+	r := New()
+	arith := PBArith(0)
+	err := r.Register("Arith", &arith, "")
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	pretty.Println(r.Services["PBArith"].String())
+}