fix bugs in docs

src/site/docs/library-tour/index.markdown

Index: src/site/docs/library-tour/index.markdown
diff --git a/src/site/docs/library-tour/index.markdown b/src/site/docs/library-tour/index.markdown
index f7fb6dc8e6f0f61dda86cfbde101d063c553f4cc..099d6f486d14b51401e438b4c704e38dd8789a43 100644
--- a/src/site/docs/library-tour/index.markdown
+++ b/src/site/docs/library-tour/index.markdown
@@ -862,7 +862,7 @@ Future deleteDone = deleteLotsOfFiles();
 Future copyDone = copyLotsOfFiles();
 Future checksumDone = checksumLotsOfOtherFiles();
 
-Futures.join([deleteDone, copyDone, checksumDone]).then(() {
+Futures.wait([deleteDone, copyDone, checksumDone]).then((List values) {
   print('Done with all the long steps');
 });
 {% endhighlight %}