Make hasNext a getter instead of a method.

samples/ui_lib/util/CollectionUtils.dart

 // Copyright (c) 2011, 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.
 
 typedef num NumericValueSelector<T>(T value);
 
 /**
  * General purpose collection utilities.
  * TODO(jmesserly): make these top level functions?
  */
@@ skipping 53 matching lines @@
     for (final item in source) {
       if (test(item)) return item;
     }
 
     return null;
   }
 
   /** Compute the minimum of an iterable. Returns null if empty. */
   static num min(Iterable source) {
     final iter = source.iterator();
-    if (!iter.hasNext()) {
+    if (!iter.hasNext) {
       return null;
     }
     num best = iter.next();
-    while (iter.hasNext()) {
+    while (iter.hasNext) {
       best = Math.min(best, iter.next());
     }
     return best;
   }
 
   /** Compute the maximum of an iterable. Returns null if empty. */
   static num max(Iterable source) {
     final iter = source.iterator();
-    if (!iter.hasNext()) {
+    if (!iter.hasNext) {
       return null;
     }
     num best = iter.next();
-    while (iter.hasNext()) {
+    while (iter.hasNext) {
       best = Math.max(best, iter.next());
     }
     return best;
   }
 
   /** Orders an iterable by its values, or by a key selector. */
   static List orderBy(Iterable source, [NumericValueSelector selector = null]) {
     final result = new List.from(source);
     sortBy(result, selector);
     return result;
@@ skipping 11 matching lines @@
     }
   }
 
   /** Compute the sum of an iterable. An empty iterable is an error. */
   static num sum(Iterable source, [NumericValueSelector selector = null]) {
     final iter = source.iterator();
     num total = 0;
     if (selector != null) {
       do {
         total += selector(iter.next());
-      } while (iter.hasNext());
+      } while (iter.hasNext);
     } else {
       do {
         total += iter.next();
-      } while (iter.hasNext());
+      } while (iter.hasNext);
     }
     return total;
   }
 
   // TODO(jmesserly): something like should exist on Map, either a method or a
   // constructor, see bug #5340679
   static void copyMap(Map dest, Map source) {
     for (final k in source.getKeys()) {
       dest[k] = source[k];
     }
   }
 }