Clean up warnings and hints

pkg/analyzer/lib/src/summary/incremental_cache.dart

 // Copyright (c) 2016, 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.
 
 import 'dart:collection';
 import 'dart:convert';
-import 'dart:core' hide Resource;
+import 'dart:core';
 
 import 'package:analyzer/dart/element/element.dart';
 import 'package:analyzer/file_system/file_system.dart';
 import 'package:analyzer/src/generated/engine.dart';
 import 'package:analyzer/src/generated/error.dart';
 import 'package:analyzer/src/generated/source.dart';
 import 'package:analyzer/src/summary/format.dart';
 import 'package:analyzer/src/summary/idl.dart';
 import 'package:analyzer/src/summary/summarize_elements.dart';
 import 'package:convert/convert.dart';
@@ skipping 345 matching lines @@
         // It's not the most efficient algorithm, but in practice we might
         // visit each library multiple times only for the first top-level
         // bundle requested in `getLibraryClosureBundles`.
         List<Source> refClosure = _libraryClosureMap[refSource];
         if (refClosure != null) {
           closure.addAll(refClosure);
         } else {
           _appendLibraryClosure(closure, refSource);
         }
       }
+
       contentSource.importedUris.forEach(appendLibrarySources);
       contentSource.exportedUris.forEach(appendLibrarySources);
     }
   }
 
   List<int> _computeSaltedMD5OfBytes(addData(ByteConversionSink byteSink)) {
     Digest digest;
     ChunkedConversionSink<Digest> digestSink =
         new ChunkedConversionSink<Digest>.withCallback((List<Digest> digests) {
       digest = digests.single;
@@ skipping 263 matching lines @@
    */
   final String id;
 
   /**
    * The payload bundle.
    */
   final PackageBundle bundle;
 
   LibraryBundleWithId(this.source, this.id, this.bundle);
 }