Upgrading tests with unittest deprecations

tests/isolate/illegal_msg_function_test.dart

Index: tests/isolate/illegal_msg_function_test.dart
diff --git a/tests/isolate/illegal_msg_function_test.dart b/tests/isolate/illegal_msg_function_test.dart
index 876799413c0a01bcb409f7332b6f625eea1a3ff2..5493abe504be7dddc7877184c3dc67d28b219a04 100644
--- a/tests/isolate/illegal_msg_function_test.dart
+++ b/tests/isolate/illegal_msg_function_test.dart
@@ -27,7 +27,7 @@ void main([args, port]) {
     Future spawn = Isolate.spawn(echo, port.sendPort);
     var caught_exception = false;
     var stream = port.asBroadcastStream();
-    stream.first.then(expectAsync1((snd) {
+    stream.first.then(expectAsync((snd) {
       try {
         snd.send(function);
       } catch (e) {
@@ -37,7 +37,7 @@ void main([args, port]) {
       if (caught_exception) {
         port.close();
       } else {
-        stream.first.then(expectAsync1((msg) {
+        stream.first.then(expectAsync((msg) {
           print("from worker ${msg}");
         }));
       }