Contrib SSH : can't import on Windows due to posix pipe use

I have set up an async SSHD on my Windows 10 box and I had to patch contrib/ssh/server.py in order to do it. The problem is that we import prompt_toolkit.input.posix_pipe at the top, when we need to be versatile to platform and import prompt_toolkit.input.win32_pipe on Windows platforms instead.

Here's how I'm handling this locally:

--- a/prompt_toolkit/contrib/ssh/server.py      2020-05-29 13:15:17.950284900 -0700
+++ b/prompt_toolkit/contrib/ssh/server.py      2020-05-29 13:27:21.302283000 -0700
@@ -9,7 +9,14 @@

 from prompt_toolkit.application.current import AppSession, create_app_session
 from prompt_toolkit.data_structures import Size
-from prompt_toolkit.input.posix_pipe import PosixPipeInput
+from importlib import import_module
+from prompt_toolkit.utils import is_windows
+if (is_windows()):
+    pipe_module = import_module('prompt_toolkit.input.win32_pipe')
+    pipe_input  = pipe_module.Win32PipeInput
+else:
+    pipe_module = import_module('prompt_toolkit.input.posix_pipe')
+    pipe_input  = pipe_module.PosixPipeInput
 from prompt_toolkit.output.vt100 import Vt100_Output

 __all__ = [
@@ -27,7 +34,7 @@
         # PipInput object, for sending input in the CLI.
         # (This is something that we can use in the prompt_toolkit event loop,
         # but still write date in manually.)
-        self._input = PosixPipeInput()
+        self._input = pipe_input()

         # Output object. Don't render to the real stdout, but write everything
         # in the SSH channel.

Start with contrib/ssh/server.py and inspect how its pipe input is imported and initialized. Make the SSH server select the platform-appropriate pipe input so async SSHD setup works on Windows while preserving POSIX behavior, then verify both import paths and Windows initialization.