update separate extension

lib/ansu_ui.dart

@@ -38,3 +38,4 @@ export 'extension/separate_extension.dart';
 
 //`BOTTOM` is external lib
 export 'package:flutter_screenutil/flutter_screenutil.dart';
+export 'package:flutter_easyrefresh/easy_refresh.dart';

lib/extension/separate_extension.dart

@@ -1,8 +1,6 @@
 import 'package:ansu_ui/ansu_ui.dart';
-import 'package:flutter/material.dart';
-
-extension SeparateExt on List {
-  List sep([Widget separate]) {
+extension SeparateExt<T> on List {
+  List<T> sep([T separate]) {
     return List.generate(this.length * 2 - 1, (index) {
       if (index.isEven)
         return this[index ~/ 2];