Update charted to 0.4.8 and roll

packages/unittest/lib/src/matcher/operator_matchers.dart

Index: packages/unittest/lib/src/matcher/operator_matchers.dart
diff --git a/packages/unittest/lib/src/matcher/operator_matchers.dart b/packages/unittest/lib/src/matcher/operator_matchers.dart
index 432f905ebc58739aaa8e75891fb8e483e3197330..cb4ee33dc3021048fce791fffae2c8e9b7e613ee 100644
--- a/packages/unittest/lib/src/matcher/operator_matchers.dart
+++ b/packages/unittest/lib/src/matcher/operator_matchers.dart
@@ -91,7 +91,7 @@ class _AnyOf extends Matcher {
 }
 
 List<Matcher> _wrapArgs(arg0, arg1, arg2, arg3, arg4, arg5, arg6) {
-  Iterable<Matcher> matchers;
+  Iterable args;
   if (arg0 is List) {
     if (arg1 != null ||
         arg2 != null ||
@@ -103,11 +103,10 @@ List<Matcher> _wrapArgs(arg0, arg1, arg2, arg3, arg4, arg5, arg6) {
           ' null.');
     }
 
-    matchers = arg0;
+    args = arg0;
   } else {
-    matchers =
-        [arg0, arg1, arg2, arg3, arg4, arg5, arg6].where((e) => e != null);
+    args = [arg0, arg1, arg2, arg3, arg4, arg5, arg6].where((e) => e != null);
   }
 
-  return matchers.map((e) => wrapMatcher(e)).toList();
+  return args.map((e) => wrapMatcher(e)).toList();
 }