Getters should not have parameters.

pkg/analysis_server/test/analysis/notification_outline_test.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.
 
 library test.analysis.notification.outline;
 
 import 'dart:async';
 
 import 'package:analysis_server/src/constants.dart';
 import 'package:analysis_server/src/protocol.dart';
@@ skipping 188 matching lines @@
         {
           Outline outline = outlines_A[8];
           Element element = outline.element;
           expect(element.kind, ElementKind.GETTER);
           expect(element.name, "propA");
           {
             Location location = element.location;
             expect(location.offset, testCode.indexOf("propA => null;"));
             expect(location.length, "propA".length);
           }
-          expect(element.parameters, "");
+          expect(element.parameters, isNull);
           expect(element.returnType, "String");
         }
         {
           Outline outline = outlines_A[9];
           Element element = outline.element;
           expect(element.kind, ElementKind.SETTER);
           expect(element.name, "propB");
           {
             Location location = element.location;
             expect(location.offset, testCode.indexOf("propB(int v) {}"));
@@ skipping 534 matching lines @@
           Location location = element.location;
           expect(location.offset, testCode.indexOf("propB(int v) {}"));
           expect(location.length, "propB".length);
         }
         expect(element.parameters, "(int v)");
         expect(element.returnType, "");
       }
     });
   }
 }