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 74396d476e022b5e37b6b443feba9d50fddece1f..8aa5a3ad04751284507cde54ea7e6334cb612f41 100644
--- a/samples/swarm/swarm_ui_lib/observable/observable.dart
+++ b/samples/swarm/swarm_ui_lib/observable/observable.dart
@@ -272,6 +272,10 @@ class ObservableList<T>
     throw new UnimplementedError();
   }
 
+  List sublist(int start, [int end]) {
+    throw new UnimplementedError();
+  }
+
   List getRange(int start, int length) {
     throw new UnimplementedError();
   }