Revert "Migrating a block of dart 2:"

tests/language/class_override_test.dart

 // Copyright (c) 2012, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
-// It is a static compile time error if a method m1 overrides a method m2 and has a
+// It is a static warning if a method m1 overrides a method m2 and has a
 // different number of required parameters.
 
 class A {
   foo() {}
 }
 
 class B extends A {
-  /*@compile-error=unspecified*/ foo(a) {} 
+  foo(a) {} // //# 00: static type warning
 }
 
 main() {
-  new B().foo(42);
+  B instance = new B();
+  try {
+    instance.foo();
+  } on NoSuchMethodError catch (error) { // //# 00: continued
+  } finally {}
+  print("Success");
 }