Create fewer unnecessary lists

pkg/analyzer/test/generated/test_support.dart

 // Copyright (c) 2014, 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.
 
 // This code was auto-generated, is not intended to be edited, and is subject to
 // significant change. Please see the README file for more information.
 
 library engine.test_support;
 
 import 'dart:collection';
@@ skipping 221 matching lines @@
 
   /**
    * Assert that the number of errors that have been gathered matches the number of errors that are
    * given and that they have the expected error codes. The order in which the errors were gathered
    * is ignored.
    *
    * @param expectedErrorCodes the error codes of the errors that should have been gathered
    * @throws AssertionFailedError if a different number of errors have been gathered than were
    *           expected
    */
-  void assertErrorsWithCodes(List<ErrorCode> expectedErrorCodes) {
+  void assertErrorsWithCodes([List<ErrorCode> expectedErrorCodes = ErrorCode.EMPTY_LIST]) {
     StringBuffer buffer = new StringBuffer();
     //
     // Verify that the expected error codes have a non-empty message.
     //
     for (ErrorCode errorCode in expectedErrorCodes) {
       expect(errorCode.message.isEmpty, isFalse, reason: "Empty error code message");
     }
     //
     // Compute the expected number of each type of error.
     //
@@ skipping 385 matching lines @@
   void getContentsToReceiver(Source_ContentReceiver receiver) {
     throw new UnsupportedOperationException();
   }
   Source resolve(String uri) {
     throw new UnsupportedOperationException();
   }
   Uri resolveRelativeUri(Uri uri) {
     return new Uri(scheme: 'file', path: _name).resolveUri(uri);
   }
 }