Get rid of all the library tags.

test/error_test.dart

 // Copyright (c) 2014, 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 string_scanner.error_test;
-
 import 'package:string_scanner/string_scanner.dart';
 import 'package:test/test.dart';
 
 import 'utils.dart';
 
 void main() {
   test('defaults to the last match', () {
     var scanner = new StringScanner('foo bar baz');
     scanner.expect('foo ');
     scanner.expect('bar');
@@ skipping 123 matching lines @@
     test("if position + length is outside the string", () {
       expect(() => scanner.error("oh no!", position: 7, length: 7),
           throwsArgumentError);
     });
 
     test("if length is negative", () {
       expect(() => scanner.error("oh no!", length: -1), throwsArgumentError);
     });
   });
 }