Change getRange to sublist. Make getRange deprecated.

samples/swarm/swarm_ui_lib/observable/observable.dart

Index: samples/swarm/swarm_ui_lib/observable/observable.dart
diff --git a/samples/swarm/swarm_ui_lib/observable/observable.dart b/samples/swarm/swarm_ui_lib/observable/observable.dart
index 85c2ae6afd79bf2b02b81706c3aaf53416838957..2a8ceb794d783367a4606bb9672483a950a9605a 100644
--- a/samples/swarm/swarm_ui_lib/observable/observable.dart
+++ b/samples/swarm/swarm_ui_lib/observable/observable.dart
@@ -267,6 +267,10 @@ class ObservableList<T>
     throw new UnimplementedError();
   }
 
+  List sublist(int start, [int end]) {
+    throw new UnimplementedError();
+  }
+
   List getRange(int start, int length) {
     throw new UnimplementedError();
   }