Reapply "Rename mappedBy to map."

pkg/http/lib/src/utils.dart

Index: pkg/http/lib/src/utils.dart
diff --git a/pkg/http/lib/src/utils.dart b/pkg/http/lib/src/utils.dart
index e1b952e8aecbd8a232be3c5cfe0752446d44e60f..c61733ef0c6f1b342ffa7eca0410443c1a8d056e 100644
--- a/pkg/http/lib/src/utils.dart
+++ b/pkg/http/lib/src/utils.dart
@@ -38,7 +38,7 @@ String mapToQuery(Map<String, String> map) {
   var pairs = <List<String>>[];
   map.forEach((key, value) =>
       pairs.add([encodeUriComponent(key), encodeUriComponent(value)]));
-  return Strings.join(pairs.mappedBy((pair) => "${pair[0]}=${pair[1]}"), "&");
+  return Strings.join(pairs.map((pair) => "${pair[0]}=${pair[1]}"), "&");
 }
 
 /// Adds all key/value pairs from [source] to [destination], overwriting any