Get rid of all the library tags.

lib/src/solver/unselected_package_queue.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 pub.solver.unselected_package_queue;
-
 import 'dart:async';
 import 'dart:collection';
 
 import 'package:stack_trace/stack_trace.dart';
 
 import '../log.dart' as log;
 import '../package.dart';
 import 'backtracking_solver.dart';
 
 /// A priority queue of package references.
@@ skipping 123 matching lines @@
           .length;
     }
 
     // TODO(nweiz): Also ignore versions with non-matching SDK constraints or
     // dependencies that are incompatible with the root package's.
     return versions.length;
   }
 
   String toString() => _set.toString();
 }