Get rid of a lot of () for getters.

utils/archive/options.dart

Index: utils/archive/options.dart
diff --git a/utils/archive/options.dart b/utils/archive/options.dart
index 77dbb6b5b2ab9baf1872ff004a45706e5f028e93..36c9e4251260dc3b75b9d013be52a2581b6868b3 100644
--- a/utils/archive/options.dart
+++ b/utils/archive/options.dart
@@ -30,7 +30,7 @@ class ArchiveOptions {
   ArchiveOptions() : _options = <String, ArchiveOption>{};
 
   /** Returns whether any options have been set. */
-  bool get isEmpty() => _options.isEmpty();
+  bool get isEmpty => _options.isEmpty();
 
   /**
    * Sets an option. [value] should either be a bool or something with a
@@ -48,5 +48,5 @@ class ArchiveOptions {
   }
 
   /** Gets all options. */
-  List<ArchiveOption> get all() => _options.getValues();
+  List<ArchiveOption> get all => _options.getValues();
 }