Make hasNext a getter instead of a method.

pkg/unittest/core_matchers.dart

Index: pkg/unittest/core_matchers.dart
diff --git a/pkg/unittest/core_matchers.dart b/pkg/unittest/core_matchers.dart
index 9d9d17237d1d91e40d574b2b9015f67fb592951f..e9278b0070847c4dfbf379f1731b4bd8656a9ffd 100644
--- a/pkg/unittest/core_matchers.dart
+++ b/pkg/unittest/core_matchers.dart
@@ -102,8 +102,8 @@ class _DeepMatcher extends BaseMatcher {
     var position = 0;
     String reason = null;
     while (reason == null) {
-      if (expectedIterator.hasNext()) {
-        if (actualIterator.hasNext()) {
+      if (expectedIterator.hasNext) {
+        if (actualIterator.hasNext) {
           Description r = matcher(expectedIterator.next(),
                            actualIterator.next(),
                            'mismatch at position ${position}',
@@ -113,7 +113,7 @@ class _DeepMatcher extends BaseMatcher {
         } else {
           reason = 'shorter than expected';
         }
-      } else if (actualIterator.hasNext()) {
+      } else if (actualIterator.hasNext) {
         reason = 'longer than expected';
       } else {
         return null;