Taken from upstream: https://github.com/pdoc3/pdoc/commit/4aa70de2221a34a3003a7e5f52a9b91965f0e359.patch.

From 4aa70de2221a34a3003a7e5f52a9b91965f0e359 Mon Sep 17 00:00:00 2001
From: Spencer Baugh <sbaugh@catern.com>
Date: Thu, 23 Sep 2021 09:00:25 -0400
Subject: [PATCH] TST: use explicit ClassWithNew instead of typing.Generic

typing.Generic doesn't have a __new__ method in 3.9.

Fixes https://github.com/pdoc3/pdoc/issues/355
---
 pdoc/test/__init__.py | 10 +++++++---
 1 file changed, 7 insertions(+), 3 deletions(-)

diff --git a/pdoc/test/__init__.py b/pdoc/test/__init__.py
index e8c3d94..8b67ab7 100644
--- a/pdoc/test/__init__.py
+++ b/pdoc/test/__init__.py
@@ -1043,16 +1043,20 @@ class C2:
 
         self.assertEqual(pdoc.Class('C2', mod, C2).params(), ['a', 'b', 'c=None', '*', 'd=1', 'e'])
 
-        class G(typing.Generic[T]):
+        class ClassWithNew:
+            def __new__(self, arg):
+                pass
+
+        class G(ClassWithNew):
             def __init__(self, a, b, c=100):
                 pass
 
         self.assertEqual(pdoc.Class('G', mod, G).params(), ['a', 'b', 'c=100'])
 
-        class G2(typing.Generic[T]):
+        class G2(ClassWithNew):
             pass
 
-        self.assertEqual(pdoc.Class('G2', mod, G2).params(), ['*args', '**kwds'])
+        self.assertEqual(pdoc.Class('G2', mod, G2).params(), ['arg'])
 
     def test_url(self):
         mod = pdoc.Module(EXAMPLE_MODULE)
d=c2d7e800e6788277bc56f31d5836f9d507dc1506'>diff</a></td><td class='form'><form class='right' method='get' action='/guix/log/gnu/services.scm'>
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<div class='path'>path: <a href='/guix/log/?id=c2d7e800e6788277bc56f31d5836f9d507dc1506'>root</a>/<a href='/guix/log/gnu?id=c2d7e800e6788277bc56f31d5836f9d507dc1506'>gnu</a>/<a href='/guix/log/gnu/services.scm?id=c2d7e800e6788277bc56f31d5836f9d507dc1506'>services.scm</a></div><div class='content'><table class='list nowrap'><tr class='nohover'><th class='left'>Age</th><th class='left'>Commit message (<a href='/guix/log/gnu/services.scm?id=c2d7e800e6788277bc56f31d5836f9d507dc1506&amp;showmsg=1'>Expand</a>)</th><th class='left'>Author</th></tr>
<tr><td><span title='2019-12-07 00:59:56 +0100'>2019-12-07</span></td><td><a href='/guix/commit/gnu/services.scm?id=33b7cb7a595aa33051648039d417338110e5a45e'>services: Add 'provenance-service-type'.</a><span class='msg-avail'>...</span></td><td>Ludovic Courtès</td></tr>
<tr><td><span title='2019-11-09 23:04:14 +0100'>2019-11-09</span></td><td><a href='/guix/commit/gnu/services.scm?id=2a4309de43011f87b3a5044c3d956c261ae151e4'>services: 'fold-services' memoizes service values.</a><span class='msg-avail'>...</span></td><td>Ludovic Courtès</td></tr>
<tr><td><span title='2019-08-14 15:38:13 -0400'>2019-08-14</span></td><td><a href='/guix/commit/gnu/services.scm?id=03cbd94d4880f1bb55d98907b48396e5120c1733'>remote: Remove '--system' argument.</a><span class='msg-avail'>...</span></td><td>Jakob L. Kreuze</td></tr>
<tr><td><span title='2019-05-10 23:29:18 +0200'>2019-05-10</span></td><td><a href='/guix/commit/gnu/services.scm?id=dc5729a8e0e2ef5cf5855aa5f1d7ecba319c2e5b'>services: 'gc-root-service-type' now has a default value.</a><span class='msg-avail'>...</span></td><td>Ludovic Courtès</td></tr>