Update charted to 0.4.8 and roll

packages/quiver/lib/check.dart

Index: packages/quiver/lib/check.dart
diff --git a/packages/quiver/lib/check.dart b/packages/quiver/lib/check.dart
index abbefb6ee9a439e894ba5aa770df51fcbb143247..58b7a1185ceb2b3fb436dcb40c49d83cebe4a69a 100644
--- a/packages/quiver/lib/check.dart
+++ b/packages/quiver/lib/check.dart
@@ -58,7 +58,7 @@ int checkListIndex(int index, int size, {message}) {
 
 /// Throws an [ArgumentError] if the given [reference] is `null`. Otherwise,
 /// returns the [reference] parameter.
-dynamic checkNotNull(reference, {message}) {
+T checkNotNull<T>(T reference, {message}) {
   if (reference == null) {
     throw new ArgumentError(_resolveMessage(message, 'null pointer'));
   }