Added additional comments

network_programming/tcp/ch3/dail_test.go

@@ -9,6 +9,7 @@ import (
 func TestDial(t *testing.T) {
 	//create a listener on a random port to make out test connection to
 	listener, err := net.Listen("tcp", "127.0.0.1:0")
+	t.Log("Test server listening on:", listener.Addr().String())
 	if err != nil {
 		t.Fatal(err)
 	}
@@ -41,6 +42,7 @@ func TestDial(t *testing.T) {
 					if err != nil {
 						// c.Read returns io.EOF when FIN packet (graceful termination) is received
 						if err != io.EOF {
+							t.Log("FIN packet received.")
 							t.Error(err)
 						}
 						return