Uploaded Test files

venv/Lib/site-packages/tornado/test/ioloop_test.py

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+from concurrent.futures import ThreadPoolExecutor
+from concurrent import futures
+import contextlib
+import datetime
+import functools
+import socket
+import subprocess
+import sys
+import threading
+import time
+import types
+from unittest import mock
+import unittest
+
+from tornado.escape import native_str
+from tornado import gen
+from tornado.ioloop import IOLoop, TimeoutError, PeriodicCallback
+from tornado.log import app_log
+from tornado.testing import AsyncTestCase, bind_unused_port, ExpectLog, gen_test
+from tornado.test.util import skipIfNonUnix, skipOnTravis
+
+import typing
+
+if typing.TYPE_CHECKING:
+    from typing import List  # noqa: F401
+
+
+class TestIOLoop(AsyncTestCase):
+    def test_add_callback_return_sequence(self):
+        # A callback returning {} or [] shouldn't spin the CPU, see Issue #1803.
+        self.calls = 0
+
+        loop = self.io_loop
+        test = self
+        old_add_callback = loop.add_callback
+
+        def add_callback(self, callback, *args, **kwargs):
+            test.calls += 1
+            old_add_callback(callback, *args, **kwargs)
+
+        loop.add_callback = types.MethodType(add_callback, loop)  # type: ignore
+        loop.add_callback(lambda: {})  # type: ignore
+        loop.add_callback(lambda: [])  # type: ignore
+        loop.add_timeout(datetime.timedelta(milliseconds=50), loop.stop)
+        loop.start()
+        self.assertLess(self.calls, 10)
+
+    @skipOnTravis
+    def test_add_callback_wakeup(self):
+        # Make sure that add_callback from inside a running IOLoop
+        # wakes up the IOLoop immediately instead of waiting for a timeout.
+        def callback():
+            self.called = True
+            self.stop()
+
+        def schedule_callback():
+            self.called = False
+            self.io_loop.add_callback(callback)
+            # Store away the time so we can check if we woke up immediately
+            self.start_time = time.time()
+
+        self.io_loop.add_timeout(self.io_loop.time(), schedule_callback)
+        self.wait()
+        self.assertAlmostEqual(time.time(), self.start_time, places=2)
+        self.assertTrue(self.called)
+
+    @skipOnTravis
+    def test_add_callback_wakeup_other_thread(self):
+        def target():
+            # sleep a bit to let the ioloop go into its poll loop
+            time.sleep(0.01)
+            self.stop_time = time.time()
+            self.io_loop.add_callback(self.stop)
+
+        thread = threading.Thread(target=target)
+        self.io_loop.add_callback(thread.start)
+        self.wait()
+        delta = time.time() - self.stop_time
+        self.assertLess(delta, 0.1)
+        thread.join()
+
+    def test_add_timeout_timedelta(self):
+        self.io_loop.add_timeout(datetime.timedelta(microseconds=1), self.stop)
+        self.wait()
+
+    def test_multiple_add(self):
+        sock, port = bind_unused_port()
+        try:
+            self.io_loop.add_handler(
+                sock.fileno(), lambda fd, events: None, IOLoop.READ
+            )
+            # Attempting to add the same handler twice fails
+            # (with a platform-dependent exception)
+            self.assertRaises(
+                Exception,
+                self.io_loop.add_handler,
+                sock.fileno(),
+                lambda fd, events: None,
+                IOLoop.READ,
+            )
+        finally:
+            self.io_loop.remove_handler(sock.fileno())
+            sock.close()
+
+    def test_remove_without_add(self):
+        # remove_handler should not throw an exception if called on an fd
+        # was never added.
+        sock, port = bind_unused_port()
+        try:
+            self.io_loop.remove_handler(sock.fileno())
+        finally:
+            sock.close()
+
+    def test_add_callback_from_signal(self):
+        # cheat a little bit and just run this normally, since we can't
+        # easily simulate the races that happen with real signal handlers
+        self.io_loop.add_callback_from_signal(self.stop)
+        self.wait()
+
+    def test_add_callback_from_signal_other_thread(self):
+        # Very crude test, just to make sure that we cover this case.
+        # This also happens to be the first test where we run an IOLoop in
+        # a non-main thread.
+        other_ioloop = IOLoop()
+        thread = threading.Thread(target=other_ioloop.start)
+        thread.start()
+        other_ioloop.add_callback_from_signal(other_ioloop.stop)
+        thread.join()
+        other_ioloop.close()
+
+    def test_add_callback_while_closing(self):
+        # add_callback should not fail if it races with another thread
+        # closing the IOLoop. The callbacks are dropped silently
+        # without executing.
+        closing = threading.Event()
+
+        def target():
+            other_ioloop.add_callback(other_ioloop.stop)
+            other_ioloop.start()
+            closing.set()
+            other_ioloop.close(all_fds=True)
+
+        other_ioloop = IOLoop()
+        thread = threading.Thread(target=target)
+        thread.start()
+        closing.wait()
+        for i in range(1000):
+            other_ioloop.add_callback(lambda: None)
+
+    @skipIfNonUnix  # just because socketpair is so convenient
+    def test_read_while_writeable(self):
+        # Ensure that write events don't come in while we're waiting for
+        # a read and haven't asked for writeability. (the reverse is
+        # difficult to test for)
+        client, server = socket.socketpair()
+        try:
+
+            def handler(fd, events):
+                self.assertEqual(events, IOLoop.READ)
+                self.stop()
+
+            self.io_loop.add_handler(client.fileno(), handler, IOLoop.READ)
+            self.io_loop.add_timeout(
+                self.io_loop.time() + 0.01, functools.partial(server.send, b"asdf")  # type: ignore
+            )
+            self.wait()
+            self.io_loop.remove_handler(client.fileno())
+        finally:
+            client.close()
+            server.close()
+
+    def test_remove_timeout_after_fire(self):
+        # It is not an error to call remove_timeout after it has run.
+        handle = self.io_loop.add_timeout(self.io_loop.time(), self.stop)
+        self.wait()
+        self.io_loop.remove_timeout(handle)
+
+    def test_remove_timeout_cleanup(self):
+        # Add and remove enough callbacks to trigger cleanup.
+        # Not a very thorough test, but it ensures that the cleanup code
+        # gets executed and doesn't blow up.  This test is only really useful
+        # on PollIOLoop subclasses, but it should run silently on any
+        # implementation.
+        for i in range(2000):
+            timeout = self.io_loop.add_timeout(self.io_loop.time() + 3600, lambda: None)
+            self.io_loop.remove_timeout(timeout)
+        # HACK: wait two IOLoop iterations for the GC to happen.
+        self.io_loop.add_callback(lambda: self.io_loop.add_callback(self.stop))
+        self.wait()
+
+    def test_remove_timeout_from_timeout(self):
+        calls = [False, False]
+
+        # Schedule several callbacks and wait for them all to come due at once.
+        # t2 should be cancelled by t1, even though it is already scheduled to
+        # be run before the ioloop even looks at it.
+        now = self.io_loop.time()
+
+        def t1():
+            calls[0] = True
+            self.io_loop.remove_timeout(t2_handle)
+
+        self.io_loop.add_timeout(now + 0.01, t1)
+
+        def t2():
+            calls[1] = True
+
+        t2_handle = self.io_loop.add_timeout(now + 0.02, t2)
+        self.io_loop.add_timeout(now + 0.03, self.stop)
+        time.sleep(0.03)
+        self.wait()
+        self.assertEqual(calls, [True, False])
+
+    def test_timeout_with_arguments(self):
+        # This tests that all the timeout methods pass through *args correctly.
+        results = []  # type: List[int]
+        self.io_loop.add_timeout(self.io_loop.time(), results.append, 1)
+        self.io_loop.add_timeout(datetime.timedelta(seconds=0), results.append, 2)
+        self.io_loop.call_at(self.io_loop.time(), results.append, 3)
+        self.io_loop.call_later(0, results.append, 4)
+        self.io_loop.call_later(0, self.stop)
+        self.wait()
+        # The asyncio event loop does not guarantee the order of these
+        # callbacks.
+        self.assertEqual(sorted(results), [1, 2, 3, 4])
+
+    def test_add_timeout_return(self):
+        # All the timeout methods return non-None handles that can be
+        # passed to remove_timeout.
+        handle = self.io_loop.add_timeout(self.io_loop.time(), lambda: None)
+        self.assertFalse(handle is None)
+        self.io_loop.remove_timeout(handle)
+
+    def test_call_at_return(self):
+        handle = self.io_loop.call_at(self.io_loop.time(), lambda: None)
+        self.assertFalse(handle is None)
+        self.io_loop.remove_timeout(handle)
+
+    def test_call_later_return(self):
+        handle = self.io_loop.call_later(0, lambda: None)
+        self.assertFalse(handle is None)
+        self.io_loop.remove_timeout(handle)
+
+    def test_close_file_object(self):
+        """When a file object is used instead of a numeric file descriptor,
+        the object should be closed (by IOLoop.close(all_fds=True),
+        not just the fd.
+        """
+        # Use a socket since they are supported by IOLoop on all platforms.
+        # Unfortunately, sockets don't support the .closed attribute for
+        # inspecting their close status, so we must use a wrapper.
+        class SocketWrapper(object):
+            def __init__(self, sockobj):
+                self.sockobj = sockobj
+                self.closed = False
+
+            def fileno(self):
+                return self.sockobj.fileno()
+
+            def close(self):
+                self.closed = True
+                self.sockobj.close()
+
+        sockobj, port = bind_unused_port()
+        socket_wrapper = SocketWrapper(sockobj)
+        io_loop = IOLoop()
+        io_loop.add_handler(socket_wrapper, lambda fd, events: None, IOLoop.READ)
+        io_loop.close(all_fds=True)
+        self.assertTrue(socket_wrapper.closed)
+
+    def test_handler_callback_file_object(self):
+        """The handler callback receives the same fd object it passed in."""
+        server_sock, port = bind_unused_port()
+        fds = []
+
+        def handle_connection(fd, events):
+            fds.append(fd)
+            conn, addr = server_sock.accept()
+            conn.close()
+            self.stop()
+
+        self.io_loop.add_handler(server_sock, handle_connection, IOLoop.READ)
+        with contextlib.closing(socket.socket()) as client_sock:
+            client_sock.connect(("127.0.0.1", port))
+            self.wait()
+        self.io_loop.remove_handler(server_sock)
+        self.io_loop.add_handler(server_sock.fileno(), handle_connection, IOLoop.READ)
+        with contextlib.closing(socket.socket()) as client_sock:
+            client_sock.connect(("127.0.0.1", port))
+            self.wait()
+        self.assertIs(fds[0], server_sock)
+        self.assertEqual(fds[1], server_sock.fileno())
+        self.io_loop.remove_handler(server_sock.fileno())
+        server_sock.close()
+
+    def test_mixed_fd_fileobj(self):
+        server_sock, port = bind_unused_port()
+
+        def f(fd, events):
+            pass
+
+        self.io_loop.add_handler(server_sock, f, IOLoop.READ)
+        with self.assertRaises(Exception):
+            # The exact error is unspecified - some implementations use
+            # IOError, others use ValueError.
+            self.io_loop.add_handler(server_sock.fileno(), f, IOLoop.READ)
+        self.io_loop.remove_handler(server_sock.fileno())
+        server_sock.close()
+
+    def test_reentrant(self):
+        """Calling start() twice should raise an error, not deadlock."""
+        returned_from_start = [False]
+        got_exception = [False]
+
+        def callback():
+            try:
+                self.io_loop.start()
+                returned_from_start[0] = True
+            except Exception:
+                got_exception[0] = True
+            self.stop()
+
+        self.io_loop.add_callback(callback)
+        self.wait()
+        self.assertTrue(got_exception[0])
+        self.assertFalse(returned_from_start[0])
+
+    def test_exception_logging(self):
+        """Uncaught exceptions get logged by the IOLoop."""
+        self.io_loop.add_callback(lambda: 1 / 0)
+        self.io_loop.add_callback(self.stop)
+        with ExpectLog(app_log, "Exception in callback"):
+            self.wait()
+
+    def test_exception_logging_future(self):
+        """The IOLoop examines exceptions from Futures and logs them."""
+
+        @gen.coroutine
+        def callback():
+            self.io_loop.add_callback(self.stop)
+            1 / 0
+
+        self.io_loop.add_callback(callback)
+        with ExpectLog(app_log, "Exception in callback"):
+            self.wait()
+
+    def test_exception_logging_native_coro(self):
+        """The IOLoop examines exceptions from awaitables and logs them."""
+
+        async def callback():
+            # Stop the IOLoop two iterations after raising an exception
+            # to give the exception time to be logged.
+            self.io_loop.add_callback(self.io_loop.add_callback, self.stop)
+            1 / 0
+
+        self.io_loop.add_callback(callback)
+        with ExpectLog(app_log, "Exception in callback"):
+            self.wait()
+
+    def test_spawn_callback(self):
+        # Both add_callback and spawn_callback run directly on the IOLoop,
+        # so their errors are logged without stopping the test.
+        self.io_loop.add_callback(lambda: 1 / 0)
+        self.io_loop.add_callback(self.stop)
+        with ExpectLog(app_log, "Exception in callback"):
+            self.wait()
+        # A spawned callback is run directly on the IOLoop, so it will be
+        # logged without stopping the test.
+        self.io_loop.spawn_callback(lambda: 1 / 0)
+        self.io_loop.add_callback(self.stop)
+        with ExpectLog(app_log, "Exception in callback"):
+            self.wait()
+
+    @skipIfNonUnix
+    def test_remove_handler_from_handler(self):
+        # Create two sockets with simultaneous read events.
+        client, server = socket.socketpair()
+        try:
+            client.send(b"abc")
+            server.send(b"abc")
+
+            # After reading from one fd, remove the other from the IOLoop.
+            chunks = []
+
+            def handle_read(fd, events):
+                chunks.append(fd.recv(1024))
+                if fd is client:
+                    self.io_loop.remove_handler(server)
+                else:
+                    self.io_loop.remove_handler(client)
+
+            self.io_loop.add_handler(client, handle_read, self.io_loop.READ)
+            self.io_loop.add_handler(server, handle_read, self.io_loop.READ)
+            self.io_loop.call_later(0.1, self.stop)
+            self.wait()
+
+            # Only one fd was read; the other was cleanly removed.
+            self.assertEqual(chunks, [b"abc"])
+        finally:
+            client.close()
+            server.close()
+
+    @skipIfNonUnix
+    @gen_test
+    def test_init_close_race(self):
+        # Regression test for #2367
+        #
+        # Skipped on windows because of what looks like a bug in the
+        # proactor event loop when started and stopped on non-main
+        # threads.
+        def f():
+            for i in range(10):
+                loop = IOLoop()
+                loop.close()
+
+        yield gen.multi([self.io_loop.run_in_executor(None, f) for i in range(2)])
+
+
+# Deliberately not a subclass of AsyncTestCase so the IOLoop isn't
+# automatically set as current.
+class TestIOLoopCurrent(unittest.TestCase):
+    def setUp(self):
+        self.io_loop = None  # type: typing.Optional[IOLoop]
+        IOLoop.clear_current()
+
+    def tearDown(self):
+        if self.io_loop is not None:
+            self.io_loop.close()
+
+    def test_default_current(self):
+        self.io_loop = IOLoop()
+        # The first IOLoop with default arguments is made current.
+        self.assertIs(self.io_loop, IOLoop.current())
+        # A second IOLoop can be created but is not made current.
+        io_loop2 = IOLoop()
+        self.assertIs(self.io_loop, IOLoop.current())
+        io_loop2.close()
+
+    def test_non_current(self):
+        self.io_loop = IOLoop(make_current=False)
+        # The new IOLoop is not initially made current.
+        self.assertIsNone(IOLoop.current(instance=False))
+        # Starting the IOLoop makes it current, and stopping the loop
+        # makes it non-current. This process is repeatable.
+        for i in range(3):
+
+            def f():
+                self.current_io_loop = IOLoop.current()
+                assert self.io_loop is not None
+                self.io_loop.stop()
+
+            self.io_loop.add_callback(f)
+            self.io_loop.start()
+            self.assertIs(self.current_io_loop, self.io_loop)
+            # Now that the loop is stopped, it is no longer current.
+            self.assertIsNone(IOLoop.current(instance=False))
+
+    def test_force_current(self):
+        self.io_loop = IOLoop(make_current=True)
+        self.assertIs(self.io_loop, IOLoop.current())
+        with self.assertRaises(RuntimeError):
+            # A second make_current=True construction cannot succeed.
+            IOLoop(make_current=True)
+        # current() was not affected by the failed construction.
+        self.assertIs(self.io_loop, IOLoop.current())
+
+
+class TestIOLoopCurrentAsync(AsyncTestCase):
+    @gen_test
+    def test_clear_without_current(self):
+        # If there is no current IOLoop, clear_current is a no-op (but
+        # should not fail). Use a thread so we see the threading.Local
+        # in a pristine state.
+        with ThreadPoolExecutor(1) as e:
+            yield e.submit(IOLoop.clear_current)
+
+
+class TestIOLoopFutures(AsyncTestCase):
+    def test_add_future_threads(self):
+        with futures.ThreadPoolExecutor(1) as pool:
+
+            def dummy():
+                pass
+
+            self.io_loop.add_future(
+                pool.submit(dummy), lambda future: self.stop(future)
+            )
+            future = self.wait()
+            self.assertTrue(future.done())
+            self.assertTrue(future.result() is None)
+
+    @gen_test
+    def test_run_in_executor_gen(self):
+        event1 = threading.Event()
+        event2 = threading.Event()
+
+        def sync_func(self_event, other_event):
+            self_event.set()
+            other_event.wait()
+            # Note that return value doesn't actually do anything,
+            # it is just passed through to our final assertion to
+            # make sure it is passed through properly.
+            return self_event
+
+        # Run two synchronous functions, which would deadlock if not
+        # run in parallel.
+        res = yield [
+            IOLoop.current().run_in_executor(None, sync_func, event1, event2),
+            IOLoop.current().run_in_executor(None, sync_func, event2, event1),
+        ]
+
+        self.assertEqual([event1, event2], res)
+
+    @gen_test
+    def test_run_in_executor_native(self):
+        event1 = threading.Event()
+        event2 = threading.Event()
+
+        def sync_func(self_event, other_event):
+            self_event.set()
+            other_event.wait()
+            return self_event
+
+        # Go through an async wrapper to ensure that the result of
+        # run_in_executor works with await and not just gen.coroutine
+        # (simply passing the underlying concurrent future would do that).
+        async def async_wrapper(self_event, other_event):
+            return await IOLoop.current().run_in_executor(
+                None, sync_func, self_event, other_event
+            )
+
+        res = yield [async_wrapper(event1, event2), async_wrapper(event2, event1)]
+
+        self.assertEqual([event1, event2], res)
+
+    @gen_test
+    def test_set_default_executor(self):
+        count = [0]
+
+        class MyExecutor(futures.ThreadPoolExecutor):
+            def submit(self, func, *args):
+                count[0] += 1
+                return super().submit(func, *args)
+
+        event = threading.Event()
+
+        def sync_func():
+            event.set()
+
+        executor = MyExecutor(1)
+        loop = IOLoop.current()
+        loop.set_default_executor(executor)
+        yield loop.run_in_executor(None, sync_func)
+        self.assertEqual(1, count[0])
+        self.assertTrue(event.is_set())
+
+
+class TestIOLoopRunSync(unittest.TestCase):
+    def setUp(self):
+        self.io_loop = IOLoop()
+
+    def tearDown(self):
+        self.io_loop.close()
+
+    def test_sync_result(self):
+        with self.assertRaises(gen.BadYieldError):
+            self.io_loop.run_sync(lambda: 42)
+
+    def test_sync_exception(self):
+        with self.assertRaises(ZeroDivisionError):
+            self.io_loop.run_sync(lambda: 1 / 0)
+
+    def test_async_result(self):
+        @gen.coroutine
+        def f():
+            yield gen.moment
+            raise gen.Return(42)
+
+        self.assertEqual(self.io_loop.run_sync(f), 42)
+
+    def test_async_exception(self):
+        @gen.coroutine
+        def f():
+            yield gen.moment
+            1 / 0
+
+        with self.assertRaises(ZeroDivisionError):
+            self.io_loop.run_sync(f)
+
+    def test_current(self):
+        def f():
+            self.assertIs(IOLoop.current(), self.io_loop)
+
+        self.io_loop.run_sync(f)
+
+    def test_timeout(self):
+        @gen.coroutine
+        def f():
+            yield gen.sleep(1)
+
+        self.assertRaises(TimeoutError, self.io_loop.run_sync, f, timeout=0.01)
+
+    def test_native_coroutine(self):
+        @gen.coroutine
+        def f1():
+            yield gen.moment
+
+        async def f2():
+            await f1()
+
+        self.io_loop.run_sync(f2)
+
+
+class TestPeriodicCallbackMath(unittest.TestCase):
+    def simulate_calls(self, pc, durations):
+        """Simulate a series of calls to the PeriodicCallback.
+
+        Pass a list of call durations in seconds (negative values
+        work to simulate clock adjustments during the call, or more or
+        less equivalently, between calls). This method returns the
+        times at which each call would be made.
+        """
+        calls = []
+        now = 1000
+        pc._next_timeout = now
+        for d in durations:
+            pc._update_next(now)
+            calls.append(pc._next_timeout)
+            now = pc._next_timeout + d
+        return calls
+
+    def dummy(self):
+        pass
+
+    def test_basic(self):
+        pc = PeriodicCallback(self.dummy, 10000)
+        self.assertEqual(
+            self.simulate_calls(pc, [0] * 5), [1010, 1020, 1030, 1040, 1050]
+        )
+
+    def test_overrun(self):
+        # If a call runs for too long, we skip entire cycles to get
+        # back on schedule.
+        call_durations = [9, 9, 10, 11, 20, 20, 35, 35, 0, 0, 0]
+        expected = [
+            1010,
+            1020,
+            1030,  # first 3 calls on schedule
+            1050,
+            1070,  # next 2 delayed one cycle
+            1100,
+            1130,  # next 2 delayed 2 cycles
+            1170,
+            1210,  # next 2 delayed 3 cycles
+            1220,
+            1230,  # then back on schedule.
+        ]
+
+        pc = PeriodicCallback(self.dummy, 10000)
+        self.assertEqual(self.simulate_calls(pc, call_durations), expected)
+
+    def test_clock_backwards(self):
+        pc = PeriodicCallback(self.dummy, 10000)
+        # Backwards jumps are ignored, potentially resulting in a
+        # slightly slow schedule (although we assume that when
+        # time.time() and time.monotonic() are different, time.time()
+        # is getting adjusted by NTP and is therefore more accurate)
+        self.assertEqual(
+            self.simulate_calls(pc, [-2, -1, -3, -2, 0]), [1010, 1020, 1030, 1040, 1050]
+        )
+
+        # For big jumps, we should perhaps alter the schedule, but we
+        # don't currently. This trace shows that we run callbacks
+        # every 10s of time.time(), but the first and second calls are
+        # 110s of real time apart because the backwards jump is
+        # ignored.
+        self.assertEqual(self.simulate_calls(pc, [-100, 0, 0]), [1010, 1020, 1030])
+
+    def test_jitter(self):
+        random_times = [0.5, 1, 0, 0.75]
+        expected = [1010, 1022.5, 1030, 1041.25]
+        call_durations = [0] * len(random_times)
+        pc = PeriodicCallback(self.dummy, 10000, jitter=0.5)
+
+        def mock_random():
+            return random_times.pop(0)
+
+        with mock.patch("random.random", mock_random):
+            self.assertEqual(self.simulate_calls(pc, call_durations), expected)
+
+
+class TestIOLoopConfiguration(unittest.TestCase):
+    def run_python(self, *statements):
+        stmt_list = [
+            "from tornado.ioloop import IOLoop",
+            "classname = lambda x: x.__class__.__name__",
+        ] + list(statements)
+        args = [sys.executable, "-c", "; ".join(stmt_list)]
+        return native_str(subprocess.check_output(args)).strip()
+
+    def test_default(self):
+        # When asyncio is available, it is used by default.
+        cls = self.run_python("print(classname(IOLoop.current()))")
+        self.assertEqual(cls, "AsyncIOMainLoop")
+        cls = self.run_python("print(classname(IOLoop()))")
+        self.assertEqual(cls, "AsyncIOLoop")
+
+    def test_asyncio(self):
+        cls = self.run_python(
+            'IOLoop.configure("tornado.platform.asyncio.AsyncIOLoop")',
+            "print(classname(IOLoop.current()))",
+        )
+        self.assertEqual(cls, "AsyncIOMainLoop")
+
+    def test_asyncio_main(self):
+        cls = self.run_python(
+            "from tornado.platform.asyncio import AsyncIOMainLoop",
+            "AsyncIOMainLoop().install()",
+            "print(classname(IOLoop.current()))",
+        )
+        self.assertEqual(cls, "AsyncIOMainLoop")
+
+
+if __name__ == "__main__":
+    unittest.main()