feat: upate darts

cli_sample/bin/cli_sample.dart

@@ -1,6 +1,28 @@
+import 'dart:io';
+
 import 'package:cli_sample/cli_sample.dart' as cli_sample;
 
-void main(List<String> arguments) {
-  final caculate_result = cli_sample.calculate();
-  print('Hello world: ${caculate_result}!');
+Future<void> main(List<String> arguments) async {
+  print("Started");
+  for (int i = 0; i < 2; i++) {
+    print("- ${DateTime.now()}");
+    await cli_sample.sleep(1);
+  }
+  print("Calculated");
+  final calculated_result = cli_sample.power();
+  print('Hello world: ${calculated_result}!');
+  print("Ended");
+
+  await for (var n in cli_sample.get_names()) {
+    print("Get: ${n}");
+  }
+
+  // print('Listen 127.0.0.1:1234 ...');
+  //
+  // final server = await HttpServer.bind('127.0.0.1', 1234);
+  // await for (final request in server) {
+  //   print('Received request: ${request}');
+  //   request.response
+  //     ..write('hello world ${DateTime.now()}');
+  // }
 }