Roll to pickup pool changes

packages/barback/lib/src/asset/asset_node_set.dart

Index: packages/barback/lib/src/asset/asset_node_set.dart
diff --git a/packages/barback/lib/src/asset/asset_node_set.dart b/packages/barback/lib/src/asset/asset_node_set.dart
index a1fc17bebcc9952dd07c2e10173244f2b4dd4afb..da55c230bfdae7b3d802720b69e56d54fd405d0c 100644
--- a/packages/barback/lib/src/asset/asset_node_set.dart
+++ b/packages/barback/lib/src/asset/asset_node_set.dart
@@ -19,8 +19,7 @@ class AssetNodeSet extends DelegatingSet<AssetNode> {
   /// A map from asset ids to assets in the set.
   final _assetsById = new Map<AssetId, AssetNode>();
 
-  AssetNodeSet()
-      : super(new Set());
+  AssetNodeSet() : super(new Set());
 
   /// Returns the asset node in the set with [id], or `null` if none exists.
   AssetNode operator [](AssetId id) => _assetsById[id];
@@ -39,4 +38,4 @@ class AssetNodeSet extends DelegatingSet<AssetNode> {
   bool containsId(AssetId id) => _assetsById.containsKey(id);
 
   void addAll(Iterable<AssetNode> nodes) => nodes.forEach(add);
-}
+}