Adjusting matcher comments with one-line summaries

pkg/matcher/lib/src/util.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 matcher.util;
 
 import 'core_matchers.dart';
 import 'interfaces.dart';
 
 /// Useful utility for nesting match states.
 void addStateInfo(Map matchState, Map values) {
   var innerState = new Map.from(matchState);
   matchState.clear();
   matchState['state'] = innerState;
   matchState.addAll(values);
 }
 
-/// Takes an argument and returns an equivalent matcher.
+/// Takes an argument and returns an equivalent [Matcher].
+///
 /// If the argument is already a matcher this does nothing,
 /// else if the argument is a function, it generates a predicate
 /// function matcher, else it generates an equals matcher.
 Matcher wrapMatcher(x) {
   if (x is Matcher) {
     return x;
   } else if (x is Function) {
     return predicate(x);
   } else {
     return equals(x);
   }
 }