chore: 添加虚拟环境到仓库

- 添加 backend_service/venv 虚拟环境
- 包含所有Python依赖包
- 注意：虚拟环境约393MB，包含12655个文件

backend_service/venv/lib/python3.13/site-packages/aioitertools/tests/helpers.py

@@ -0,0 +1,57 @@
+# Copyright 2022 Amethyst Reese
+# Licensed under the MIT license
+
+import asyncio
+import functools
+import sys
+from unittest import skipIf, TestCase
+
+from aioitertools.helpers import maybe_await
+
+
+def async_test(fn):
+    def wrapped(*args, **kwargs):
+        try:
+            loop = asyncio.new_event_loop()
+            loop.set_debug(False)
+            result = loop.run_until_complete(fn(*args, **kwargs))
+            return result
+        finally:
+            loop.close()
+
+    return wrapped
+
+
+class HelpersTest(TestCase):
+
+    # aioitertools.helpers.maybe_await()
+
+    @async_test
+    async def test_maybe_await(self):
+        self.assertEqual(await maybe_await(42), 42)
+
+    @async_test
+    async def test_maybe_await_async_def(self):
+        async def forty_two():
+            await asyncio.sleep(0.0001)
+            return 42
+
+        self.assertEqual(await maybe_await(forty_two()), 42)
+
+    @skipIf(sys.version_info >= (3, 11), "@asyncio.coroutine removed")
+    @async_test
+    async def test_maybe_await_coroutine(self):
+        @asyncio.coroutine
+        def forty_two():
+            yield from asyncio.sleep(0.0001)
+            return 42
+
+        self.assertEqual(await maybe_await(forty_two()), 42)
+
+    @async_test
+    async def test_maybe_await_partial(self):
+        async def multiply(a, b):
+            await asyncio.sleep(0.0001)
+            return a * b
+
+        self.assertEqual(await maybe_await(functools.partial(multiply, 6)(7)), 42)