Get rid of all the library tags.

lib/src/utils.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 source_span.utils;
-
 /// Returns the minimum of [obj1] and [obj2] according to
 /// [Comparable.compareTo].
 Comparable min(Comparable obj1, Comparable obj2) =>
     obj1.compareTo(obj2) > 0 ? obj2 : obj1;
 
 /// Returns the maximum of [obj1] and [obj2] according to
 /// [Comparable.compareTo].
 Comparable max(Comparable obj1, Comparable obj2) =>
     obj1.compareTo(obj2) > 0 ? obj1 : obj2;
 
 /// Finds a line in [context] containing [text] at the specified [column].
 ///
 /// Returns the index in [context] where that line begins, or null if none
 /// exists.
 int findLineStart(String context, String text, int column) {
   var isEmpty = text == '';
   var index = context.indexOf(text);
   while (index != -1) {
     var lineStart = context.lastIndexOf('\n', index) + 1;
     var textColumn = index - lineStart;
     if (column == textColumn || (isEmpty && column == textColumn + 1)) {
       return lineStart;
     }
     index = context.indexOf(text, index + 1);
   }
   return null;
 }