improve MixinBuilder

@@ -3,27 +3,7 @@ import 'package:flutter/widgets.dart';
 import 'package:get/src/state_manager/rx/rx_interface.dart';
 import 'rx_impl.dart';
 
-Widget obx(Widget Function() builder) {
-  final b = builder;
-  return Obxx(b);
-}
-
-/// it's very very very very experimental
-class Obxx extends StatelessWidget {
-  final Widget Function() builder;
-  Obxx(this.builder, {Key key}) : super(key: key);
-  final RxInterface _observer = Rx();
 
-  @override
-  Widget build(_) {
-    _observer.subject.stream.listen((data) => (_ as Element)..markNeedsBuild());
-    final observer = getObs;
-    getObs = _observer;
-    final result = builder();
-    getObs = observer;
-    return result;
-  }
-}
 
 /// The simplest reactive widget in GetX.
 ///

@@ -36,6 +36,6 @@ class MixinBuilder<T extends GetxController> extends StatelessWidget {
         id: id,
         didChangeDependencies: didChangeDependencies,
         didUpdateWidget: didUpdateWidget,
-        builder: (controller) => obx(() => builder.call(controller)));
+        builder: (controller) => Obx(() => builder.call(controller)));
   }
 }

@@ -33,7 +33,7 @@ void main() {
                   child: Text("increment"),
                   onPressed: () => controller.increment(),
                 ),
-                obx(() => Text(
+                Obx(() => Text(
                       'Obx: ${controller.map.value.length}',
                     ))
               ]),