appropriating Shailen's excellent Futures intro into tutorial

src/site/articles/using-future-based-apis/code/example5.dart

Index: src/site/articles/using-future-based-apis/code/example5.dart
diff --git a/src/site/articles/using-future-based-apis/code/example5.dart b/src/site/articles/using-future-based-apis/code/example5.dart
deleted file mode 100644
index 56563372de2b1f2fd2612bdaf1b4d68a48b51837..0000000000000000000000000000000000000000
--- a/src/site/articles/using-future-based-apis/code/example5.dart
+++ /dev/null
@@ -1,24 +0,0 @@
-import 'dart:io';
-import 'dart:async';
-
-void main() {
-  Future.wait([expensiveA(), expensiveB(), expensiveC()])
-        .then((List responses) => chooseBestResponse(responses))
-        .catchError((e) => handleError(e));
-}
-
-Future expensiveA() => new Future.value('from expensiveA');
-Future expensiveB() => new Future.value('from expensiveB');
-Future expensiveC() => new Future.value('from expensiveC');
-
-doSomethingWith(value) {
-  print(value);
-}
-
-chooseBestResponse(List responses) {
-  print(responses[1]);
-}
-
-handleError(e) {
-  print('error handled');
-}