Modernize the package's style.

lib/src/lazy_stream.dart

 // Copyright (c) 2015, 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 async.lazy_stream;
-
 import "dart:async";
 
 import "stream_completer.dart";
 
 /// A [Stream] wrapper that forwards to another [Stream] that's initialized
 /// lazily.
 ///
 /// This class allows a concrete `Stream` to be created only once it has a
 /// listener. It's useful to wrapping APIs that do expensive computation to
 /// produce a `Stream`.
@@ skipping 25 matching lines @@
     var result = callback();
 
     Stream stream = result is Future
         ? StreamCompleter.fromFuture(result)
         : result;
 
     return stream.listen(onData,
         onError: onError, onDone: onDone, cancelOnError: cancelOnError);
   }
 }