diff --git a/venv/Lib/site-packages/anyio/_core/__init__.py b/venv/Lib/site-packages/anyio/_core/__init__.py
new file mode 100644
index 0000000..06d7405
Binary files /dev/null and b/venv/Lib/site-packages/anyio/_core/__init__.py differ
diff --git a/venv/Lib/site-packages/anyio/_core/_asyncio_selector_thread.py b/venv/Lib/site-packages/anyio/_core/_asyncio_selector_thread.py
new file mode 100644
index 0000000..9f35bae
--- /dev/null
+++ b/venv/Lib/site-packages/anyio/_core/_asyncio_selector_thread.py
@@ -0,0 +1,167 @@
+from __future__ import annotations
+
+import asyncio
+import socket
+import threading
+from collections.abc import Callable
+from selectors import EVENT_READ, EVENT_WRITE, DefaultSelector
+from typing import TYPE_CHECKING, Any
+
+if TYPE_CHECKING:
+    from _typeshed import FileDescriptorLike
+
+_selector_lock = threading.Lock()
+_selector: Selector | None = None
+
+
+class Selector:
+    def __init__(self) -> None:
+        self._thread = threading.Thread(target=self.run, name="AnyIO socket selector")
+        self._selector = DefaultSelector()
+        self._send, self._receive = socket.socketpair()
+        self._send.setblocking(False)
+        self._receive.setblocking(False)
+        # This somewhat reduces the amount of memory wasted queueing up data
+        # for wakeups. With these settings, maximum number of 1-byte sends
+        # before getting BlockingIOError:
+        #   Linux 4.8: 6
+        #   macOS (darwin 15.5): 1
+        #   Windows 10: 525347
+        # Windows you're weird. (And on Windows setting SNDBUF to 0 makes send
+        # blocking, even on non-blocking sockets, so don't do that.)
+        self._receive.setsockopt(socket.SOL_SOCKET, socket.SO_RCVBUF, 1)
+        self._send.setsockopt(socket.SOL_SOCKET, socket.SO_SNDBUF, 1)
+        # On Windows this is a TCP socket so this might matter. On other
+        # platforms this fails b/c AF_UNIX sockets aren't actually TCP.
+        try:
+            self._send.setsockopt(socket.IPPROTO_TCP, socket.TCP_NODELAY, 1)
+        except OSError:
+            pass
+
+        self._selector.register(self._receive, EVENT_READ)
+        self._closed = False
+
+    def start(self) -> None:
+        self._thread.start()
+        threading._register_atexit(self._stop)  # type: ignore[attr-defined]
+
+    def _stop(self) -> None:
+        global _selector
+        self._closed = True
+        self._notify_self()
+        self._send.close()
+        self._thread.join()
+        self._selector.unregister(self._receive)
+        self._receive.close()
+        self._selector.close()
+        _selector = None
+        assert not self._selector.get_map(), (
+            "selector still has registered file descriptors after shutdown"
+        )
+
+    def _notify_self(self) -> None:
+        try:
+            self._send.send(b"\x00")
+        except BlockingIOError:
+            pass
+
+    def add_reader(self, fd: FileDescriptorLike, callback: Callable[[], Any]) -> None:
+        loop = asyncio.get_running_loop()
+        try:
+            key = self._selector.get_key(fd)
+        except KeyError:
+            self._selector.register(fd, EVENT_READ, {EVENT_READ: (loop, callback)})
+        else:
+            if EVENT_READ in key.data:
+                raise ValueError(
+                    "this file descriptor is already registered for reading"
+                )
+
+            key.data[EVENT_READ] = loop, callback
+            self._selector.modify(fd, key.events | EVENT_READ, key.data)
+
+        self._notify_self()
+
+    def add_writer(self, fd: FileDescriptorLike, callback: Callable[[], Any]) -> None:
+        loop = asyncio.get_running_loop()
+        try:
+            key = self._selector.get_key(fd)
+        except KeyError:
+            self._selector.register(fd, EVENT_WRITE, {EVENT_WRITE: (loop, callback)})
+        else:
+            if EVENT_WRITE in key.data:
+                raise ValueError(
+                    "this file descriptor is already registered for writing"
+                )
+
+            key.data[EVENT_WRITE] = loop, callback
+            self._selector.modify(fd, key.events | EVENT_WRITE, key.data)
+
+        self._notify_self()
+
+    def remove_reader(self, fd: FileDescriptorLike) -> bool:
+        try:
+            key = self._selector.get_key(fd)
+        except KeyError:
+            return False
+
+        if new_events := key.events ^ EVENT_READ:
+            del key.data[EVENT_READ]
+            self._selector.modify(fd, new_events, key.data)
+        else:
+            self._selector.unregister(fd)
+
+        return True
+
+    def remove_writer(self, fd: FileDescriptorLike) -> bool:
+        try:
+            key = self._selector.get_key(fd)
+        except KeyError:
+            return False
+
+        if new_events := key.events ^ EVENT_WRITE:
+            del key.data[EVENT_WRITE]
+            self._selector.modify(fd, new_events, key.data)
+        else:
+            self._selector.unregister(fd)
+
+        return True
+
+    def run(self) -> None:
+        while not self._closed:
+            for key, events in self._selector.select():
+                if key.fileobj is self._receive:
+                    try:
+                        while self._receive.recv(4096):
+                            pass
+                    except BlockingIOError:
+                        pass
+
+                    continue
+
+                if events & EVENT_READ:
+                    loop, callback = key.data[EVENT_READ]
+                    self.remove_reader(key.fd)
+                    try:
+                        loop.call_soon_threadsafe(callback)
+                    except RuntimeError:
+                        pass  # the loop was already closed
+
+                if events & EVENT_WRITE:
+                    loop, callback = key.data[EVENT_WRITE]
+                    self.remove_writer(key.fd)
+                    try:
+                        loop.call_soon_threadsafe(callback)
+                    except RuntimeError:
+                        pass  # the loop was already closed
+
+
+def get_selector() -> Selector:
+    global _selector
+
+    with _selector_lock:
+        if _selector is None:
+            _selector = Selector()
+            _selector.start()
+
+        return _selector
diff --git a/venv/Lib/site-packages/anyio/_core/_contextmanagers.py b/venv/Lib/site-packages/anyio/_core/_contextmanagers.py
new file mode 100644
index 0000000..302f32b
--- /dev/null
+++ b/venv/Lib/site-packages/anyio/_core/_contextmanagers.py
@@ -0,0 +1,200 @@
+from __future__ import annotations
+
+from abc import abstractmethod
+from contextlib import AbstractAsyncContextManager, AbstractContextManager
+from inspect import isasyncgen, iscoroutine, isgenerator
+from types import TracebackType
+from typing import Protocol, TypeVar, cast, final
+
+_T_co = TypeVar("_T_co", covariant=True)
+_ExitT_co = TypeVar("_ExitT_co", covariant=True, bound="bool | None")
+
+
+class _SupportsCtxMgr(Protocol[_T_co, _ExitT_co]):
+    def __contextmanager__(self) -> AbstractContextManager[_T_co, _ExitT_co]: ...
+
+
+class _SupportsAsyncCtxMgr(Protocol[_T_co, _ExitT_co]):
+    def __asynccontextmanager__(
+        self,
+    ) -> AbstractAsyncContextManager[_T_co, _ExitT_co]: ...
+
+
+class ContextManagerMixin:
+    """
+    Mixin class providing context manager functionality via a generator-based
+    implementation.
+
+    This class allows you to implement a context manager via :meth:`__contextmanager__`
+    which should return a generator. The mechanics are meant to mirror those of
+    :func:`@contextmanager <contextlib.contextmanager>`.
+
+    .. note:: Classes using this mix-in are not reentrant as context managers, meaning
+        that once you enter it, you can't re-enter before first exiting it.
+
+    .. seealso:: :doc:`contextmanagers`
+    """
+
+    __cm: AbstractContextManager[object, bool | None] | None = None
+
+    @final
+    def __enter__(self: _SupportsCtxMgr[_T_co, bool | None]) -> _T_co:
+        # Needed for mypy to assume self still has the __cm member
+        assert isinstance(self, ContextManagerMixin)
+        if self.__cm is not None:
+            raise RuntimeError(
+                f"this {self.__class__.__qualname__} has already been entered"
+            )
+
+        cm = self.__contextmanager__()
+        if not isinstance(cm, AbstractContextManager):
+            if isgenerator(cm):
+                raise TypeError(
+                    "__contextmanager__() returned a generator object instead of "
+                    "a context manager. Did you forget to add the @contextmanager "
+                    "decorator?"
+                )
+
+            raise TypeError(
+                f"__contextmanager__() did not return a context manager object, "
+                f"but {cm.__class__!r}"
+            )
+
+        if cm is self:
+            raise TypeError(
+                f"{self.__class__.__qualname__}.__contextmanager__() returned "
+                f"self. Did you forget to add the @contextmanager decorator and a "
+                f"'yield' statement?"
+            )
+
+        value = cm.__enter__()
+        self.__cm = cm
+        return value
+
+    @final
+    def __exit__(
+        self: _SupportsCtxMgr[object, _ExitT_co],
+        exc_type: type[BaseException] | None,
+        exc_val: BaseException | None,
+        exc_tb: TracebackType | None,
+    ) -> _ExitT_co:
+        # Needed for mypy to assume self still has the __cm member
+        assert isinstance(self, ContextManagerMixin)
+        if self.__cm is None:
+            raise RuntimeError(
+                f"this {self.__class__.__qualname__} has not been entered yet"
+            )
+
+        # Prevent circular references
+        cm = self.__cm
+        del self.__cm
+
+        return cast(_ExitT_co, cm.__exit__(exc_type, exc_val, exc_tb))
+
+    @abstractmethod
+    def __contextmanager__(self) -> AbstractContextManager[object, bool | None]:
+        """
+        Implement your context manager logic here.
+
+        This method **must** be decorated with
+        :func:`@contextmanager <contextlib.contextmanager>`.
+
+        .. note:: Remember that the ``yield`` will raise any exception raised in the
+            enclosed context block, so use a ``finally:`` block to clean up resources!
+
+        :return: a context manager object
+        """
+
+
+class AsyncContextManagerMixin:
+    """
+    Mixin class providing async context manager functionality via a generator-based
+    implementation.
+
+    This class allows you to implement a context manager via
+    :meth:`__asynccontextmanager__`. The mechanics are meant to mirror those of
+    :func:`@asynccontextmanager <contextlib.asynccontextmanager>`.
+
+    .. note:: Classes using this mix-in are not reentrant as context managers, meaning
+        that once you enter it, you can't re-enter before first exiting it.
+
+    .. seealso:: :doc:`contextmanagers`
+    """
+
+    __cm: AbstractAsyncContextManager[object, bool | None] | None = None
+
+    @final
+    async def __aenter__(self: _SupportsAsyncCtxMgr[_T_co, bool | None]) -> _T_co:
+        # Needed for mypy to assume self still has the __cm member
+        assert isinstance(self, AsyncContextManagerMixin)
+        if self.__cm is not None:
+            raise RuntimeError(
+                f"this {self.__class__.__qualname__} has already been entered"
+            )
+
+        cm = self.__asynccontextmanager__()
+        if not isinstance(cm, AbstractAsyncContextManager):
+            if isasyncgen(cm):
+                raise TypeError(
+                    "__asynccontextmanager__() returned an async generator instead of "
+                    "an async context manager. Did you forget to add the "
+                    "@asynccontextmanager decorator?"
+                )
+            elif iscoroutine(cm):
+                cm.close()
+                raise TypeError(
+                    "__asynccontextmanager__() returned a coroutine object instead of "
+                    "an async context manager. Did you forget to add the "
+                    "@asynccontextmanager decorator and a 'yield' statement?"
+                )
+
+            raise TypeError(
+                f"__asynccontextmanager__() did not return an async context manager, "
+                f"but {cm.__class__!r}"
+            )
+
+        if cm is self:
+            raise TypeError(
+                f"{self.__class__.__qualname__}.__asynccontextmanager__() returned "
+                f"self. Did you forget to add the @asynccontextmanager decorator and a "
+                f"'yield' statement?"
+            )
+
+        value = await cm.__aenter__()
+        self.__cm = cm
+        return value
+
+    @final
+    async def __aexit__(
+        self: _SupportsAsyncCtxMgr[object, _ExitT_co],
+        exc_type: type[BaseException] | None,
+        exc_val: BaseException | None,
+        exc_tb: TracebackType | None,
+    ) -> _ExitT_co:
+        assert isinstance(self, AsyncContextManagerMixin)
+        if self.__cm is None:
+            raise RuntimeError(
+                f"this {self.__class__.__qualname__} has not been entered yet"
+            )
+
+        # Prevent circular references
+        cm = self.__cm
+        del self.__cm
+
+        return cast(_ExitT_co, await cm.__aexit__(exc_type, exc_val, exc_tb))
+
+    @abstractmethod
+    def __asynccontextmanager__(
+        self,
+    ) -> AbstractAsyncContextManager[object, bool | None]:
+        """
+        Implement your async context manager logic here.
+
+        This method **must** be decorated with
+        :func:`@asynccontextmanager <contextlib.asynccontextmanager>`.
+
+        .. note:: Remember that the ``yield`` will raise any exception raised in the
+            enclosed context block, so use a ``finally:`` block to clean up resources!
+
+        :return: an async context manager object
+        """
diff --git a/venv/Lib/site-packages/anyio/_core/_eventloop.py b/venv/Lib/site-packages/anyio/_core/_eventloop.py
new file mode 100644
index 0000000..a3e2ab1
--- /dev/null
+++ b/venv/Lib/site-packages/anyio/_core/_eventloop.py
@@ -0,0 +1,240 @@
+from __future__ import annotations
+
+import math
+import sys
+import threading
+from collections.abc import Awaitable, Callable, Generator
+from contextlib import contextmanager
+from contextvars import Token
+from importlib import import_module
+from typing import TYPE_CHECKING, Any, TypeVar
+
+from ._exceptions import NoEventLoopError
+
+if sys.version_info >= (3, 11):
+    from typing import TypeVarTuple, Unpack
+else:
+    from typing_extensions import TypeVarTuple, Unpack
+
+sniffio: Any
+try:
+    import sniffio
+except ModuleNotFoundError:
+    sniffio = None
+
+if TYPE_CHECKING:
+    from ..abc import AsyncBackend
+
+# This must be updated when new backends are introduced
+BACKENDS = "asyncio", "trio"
+
+T_Retval = TypeVar("T_Retval")
+PosArgsT = TypeVarTuple("PosArgsT")
+
+threadlocals = threading.local()
+loaded_backends: dict[str, type[AsyncBackend]] = {}
+
+
+def run(
+    func: Callable[[Unpack[PosArgsT]], Awaitable[T_Retval]],
+    *args: Unpack[PosArgsT],
+    backend: str = "asyncio",
+    backend_options: dict[str, Any] | None = None,
+) -> T_Retval:
+    """
+    Run the given coroutine function in an asynchronous event loop.
+
+    The current thread must not be already running an event loop.
+
+    :param func: a coroutine function
+    :param args: positional arguments to ``func``
+    :param backend: name of the asynchronous event loop implementation – currently
+        either ``asyncio`` or ``trio``
+    :param backend_options: keyword arguments to call the backend ``run()``
+        implementation with (documented :ref:`here <backend options>`)
+    :return: the return value of the coroutine function
+    :raises RuntimeError: if an asynchronous event loop is already running in this
+        thread
+    :raises LookupError: if the named backend is not found
+
+    """
+    if asynclib_name := current_async_library():
+        raise RuntimeError(f"Already running {asynclib_name} in this thread")
+
+    try:
+        async_backend = get_async_backend(backend)
+    except ImportError as exc:
+        if backend in BACKENDS:
+            raise LookupError(
+                f"Backend {backend!r} is not available. "
+                f"Install it with: pip install anyio[{backend}]"
+            ) from exc
+
+        raise LookupError(f"No such backend: {backend}") from exc
+
+    token = None
+    if asynclib_name is None:
+        # Since we're in control of the event loop, we can cache the name of the async
+        # library
+        token = set_current_async_library(backend)
+
+    try:
+        backend_options = backend_options or {}
+        return async_backend.run(func, args, {}, backend_options)
+    finally:
+        reset_current_async_library(token)
+
+
+async def sleep(delay: float) -> None:
+    """
+    Pause the current task for the specified duration.
+
+    :param delay: the duration, in seconds
+
+    """
+    return await get_async_backend().sleep(delay)
+
+
+async def sleep_forever() -> None:
+    """
+    Pause the current task until it's cancelled.
+
+    This is a shortcut for ``sleep(math.inf)``.
+
+    .. versionadded:: 3.1
+
+    """
+    await sleep(math.inf)
+
+
+async def sleep_until(deadline: float) -> None:
+    """
+    Pause the current task until the given time.
+
+    :param deadline: the absolute time to wake up at (according to the internal
+        monotonic clock of the event loop)
+
+    .. versionadded:: 3.1
+
+    """
+    now = current_time()
+    await sleep(max(deadline - now, 0))
+
+
+def current_time() -> float:
+    """
+    Return the current value of the event loop's internal clock.
+
+    :return: the clock value (seconds)
+    :raises NoEventLoopError: if no supported asynchronous event loop is running in the
+        current thread
+
+    """
+    return get_async_backend().current_time()
+
+
+def get_all_backends() -> tuple[str, ...]:
+    """Return a tuple of the names of all built-in backends."""
+    return BACKENDS
+
+
+def get_available_backends() -> tuple[str, ...]:
+    """
+    Test for the availability of built-in backends.
+
+    :return a tuple of the built-in backend names that were successfully imported
+
+    .. versionadded:: 4.12
+
+    """
+    available_backends: list[str] = []
+    for backend_name in get_all_backends():
+        try:
+            get_async_backend(backend_name)
+        except ImportError:
+            continue
+
+        available_backends.append(backend_name)
+
+    return tuple(available_backends)
+
+
+def get_cancelled_exc_class() -> type[BaseException]:
+    """
+    Return the current async library's cancellation exception class.
+
+    :raises NoEventLoopError: if no supported asynchronous event loop is running in the
+        current thread
+
+    """
+    return get_async_backend().cancelled_exception_class()
+
+
+#
+# Private API
+#
+
+
+@contextmanager
+def claim_worker_thread(
+    backend_class: type[AsyncBackend], token: object
+) -> Generator[Any, None, None]:
+    from ..lowlevel import EventLoopToken
+
+    threadlocals.current_token = EventLoopToken(backend_class, token)
+    try:
+        yield
+    finally:
+        del threadlocals.current_token
+
+
+def get_async_backend(asynclib_name: str | None = None) -> type[AsyncBackend]:
+    if asynclib_name is None:
+        asynclib_name = current_async_library()
+        if not asynclib_name:
+            raise NoEventLoopError(
+                f"Not currently running on any asynchronous event loop. "
+                f"Available async backends: {', '.join(get_all_backends())}"
+            )
+
+    # We use our own dict instead of sys.modules to get the already imported back-end
+    # class because the appropriate modules in sys.modules could potentially be only
+    # partially initialized
+    try:
+        return loaded_backends[asynclib_name]
+    except KeyError:
+        module = import_module(f"anyio._backends._{asynclib_name}")
+        loaded_backends[asynclib_name] = module.backend_class
+        return module.backend_class
+
+
+def current_async_library() -> str | None:
+    if sniffio is None:
+        # If sniffio is not installed, we assume we're either running asyncio or nothing
+        import asyncio
+
+        try:
+            asyncio.get_running_loop()
+            return "asyncio"
+        except RuntimeError:
+            pass
+    else:
+        try:
+            return sniffio.current_async_library()
+        except sniffio.AsyncLibraryNotFoundError:
+            pass
+
+    return None
+
+
+def set_current_async_library(asynclib_name: str | None) -> Token | None:
+    # no-op if sniffio is not installed
+    if sniffio is None:
+        return None
+
+    return sniffio.current_async_library_cvar.set(asynclib_name)
+
+
+def reset_current_async_library(token: Token | None) -> None:
+    if token is not None:
+        sniffio.current_async_library_cvar.reset(token)
diff --git a/venv/Lib/site-packages/anyio/_core/_exceptions.py b/venv/Lib/site-packages/anyio/_core/_exceptions.py
new file mode 100644
index 0000000..cd6eb9b
--- /dev/null
+++ b/venv/Lib/site-packages/anyio/_core/_exceptions.py
@@ -0,0 +1,177 @@
+from __future__ import annotations
+
+import sys
+from collections.abc import Generator
+from textwrap import dedent
+from typing import Any
+
+if sys.version_info < (3, 11):
+    from exceptiongroup import BaseExceptionGroup
+
+
+class BrokenResourceError(Exception):
+    """
+    Raised when trying to use a resource that has been rendered unusable due to external
+    causes (e.g. a send stream whose peer has disconnected).
+    """
+
+
+class BrokenWorkerProcess(Exception):
+    """
+    Raised by :meth:`~anyio.to_process.run_sync` if the worker process terminates abruptly or
+    otherwise misbehaves.
+    """
+
+
+class BrokenWorkerInterpreter(Exception):
+    """
+    Raised by :meth:`~anyio.to_interpreter.run_sync` if an unexpected exception is
+    raised in the subinterpreter.
+    """
+
+    def __init__(self, excinfo: Any):
+        # This was adapted from concurrent.futures.interpreter.ExecutionFailed
+        msg = excinfo.formatted
+        if not msg:
+            if excinfo.type and excinfo.msg:
+                msg = f"{excinfo.type.__name__}: {excinfo.msg}"
+            else:
+                msg = excinfo.type.__name__ or excinfo.msg
+
+        super().__init__(msg)
+        self.excinfo = excinfo
+
+    def __str__(self) -> str:
+        try:
+            formatted = self.excinfo.errdisplay
+        except Exception:
+            return super().__str__()
+        else:
+            return dedent(
+                f"""
+                {super().__str__()}
+
+                Uncaught in the interpreter:
+
+                {formatted}
+                """.strip()
+            )
+
+
+class BusyResourceError(Exception):
+    """
+    Raised when two tasks are trying to read from or write to the same resource
+    concurrently.
+    """
+
+    def __init__(self, action: str):
+        super().__init__(f"Another task is already {action} this resource")
+
+
+class ClosedResourceError(Exception):
+    """Raised when trying to use a resource that has been closed."""
+
+
+class ConnectionFailed(OSError):
+    """
+    Raised when a connection attempt fails.
+
+    .. note:: This class inherits from :exc:`OSError` for backwards compatibility.
+    """
+
+
+def iterate_exceptions(
+    exception: BaseException,
+) -> Generator[BaseException, None, None]:
+    if isinstance(exception, BaseExceptionGroup):
+        for exc in exception.exceptions:
+            yield from iterate_exceptions(exc)
+    else:
+        yield exception
+
+
+class DelimiterNotFound(Exception):
+    """
+    Raised during
+    :meth:`~anyio.streams.buffered.BufferedByteReceiveStream.receive_until` if the
+    maximum number of bytes has been read without the delimiter being found.
+    """
+
+    def __init__(self, max_bytes: int) -> None:
+        super().__init__(
+            f"The delimiter was not found among the first {max_bytes} bytes"
+        )
+
+
+class EndOfStream(Exception):
+    """
+    Raised when trying to read from a stream that has been closed from the other end.
+    """
+
+
+class IncompleteRead(Exception):
+    """
+    Raised during
+    :meth:`~anyio.streams.buffered.BufferedByteReceiveStream.receive_exactly` or
+    :meth:`~anyio.streams.buffered.BufferedByteReceiveStream.receive_until` if the
+    connection is closed before the requested amount of bytes has been read.
+    """
+
+    def __init__(self) -> None:
+        super().__init__(
+            "The stream was closed before the read operation could be completed"
+        )
+
+
+class TypedAttributeLookupError(LookupError):
+    """
+    Raised by :meth:`~anyio.TypedAttributeProvider.extra` when the given typed attribute
+    is not found and no default value has been given.
+    """
+
+
+class WouldBlock(Exception):
+    """Raised by ``X_nowait`` functions if ``X()`` would block."""
+
+
+class NoEventLoopError(RuntimeError):
+    """
+    Raised by several functions that require an event loop to be running in the current
+    thread when there is no running event loop.
+
+    This is also raised by :func:`.from_thread.run` and :func:`.from_thread.run_sync`
+    if not calling from an AnyIO worker thread, and no ``token`` was passed.
+    """
+
+
+class RunFinishedError(RuntimeError):
+    """
+    Raised by :func:`.from_thread.run` and :func:`.from_thread.run_sync` if the event
+    loop associated with the explicitly passed token has already finished.
+    """
+
+    def __init__(self) -> None:
+        super().__init__(
+            "The event loop associated with the given token has already finished"
+        )
+
+
+class TaskFailed(Exception):
+    """
+    Raised when awaiting on, or attempting to access the return value of, a
+    :class:`.TaskHandle` that raised an exception.
+    """
+
+
+class TaskCancelled(TaskFailed):
+    """
+    Raised when awaiting on, or attempting to access the return value of, a
+    :class:`.TaskHandle` that was cancelled.
+    """
+
+
+class TaskNotFinished(Exception):
+    """
+    Raised when attempting to access the return value or exception of a
+    :class:`.TaskHandle` that is still pending completion.
+    """