Roll to pickup pool changes

packages/barback/lib/src/transformer/transformer.dart

 // Copyright (c) 2013, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 library barback.transformer.transformer;
 
 import 'dart:async';
 
 import '../asset/asset_id.dart';
 import '../utils.dart';
@@ skipping 15 matching lines @@
   /// Each extension must begin with a leading `.`.
   ///
   /// If you don't override [isPrimary] yourself, it defaults to allowing any
   /// asset whose extension matches one of the ones returned by this. If you
   /// don't override [isPrimary] *or* this, it allows all files.
   String get allowedExtensions => null;
 
   Transformer() {
     if (allowedExtensions == null) return;
 
-    var invalidExtensions = allowedExtensions.split(" ")
+    var invalidExtensions = allowedExtensions
+        .split(" ")
         .where((extension) => !extension.startsWith("."))
         .map((extension) => '"$extension"');
     if (invalidExtensions.isEmpty) return;
 
     throw new FormatException('Each extension in $this.allowedExtensions '
         'must begin with a ".", but ${toSentence(invalidExtensions)} '
         '${pluralize("doesn't", invalidExtensions.length, plural: "don't")}.');
   }
 
   /// Returns `true` if [id] can be a primary input for this transformer.
@@ skipping 37 matching lines @@
   /// In other words, a Transformer's job is to find all inputs for a
   /// transform, starting at the primary input, then generate all output assets
   /// and yield them back to the transform.
   ///
   /// If this does asynchronous work, it should return a [Future] that completes
   /// once it's finished.
   apply(Transform transform);
 
   String toString() => runtimeType.toString().replaceAll("Transformer", "");
 }