https://github.com/izimobil/polib/issues/136

--- polib-1.2.0.orig/tox.ini
+++ polib-1.2.0/tox.ini
@@ -0,0 +1,28 @@
+[tox]
+envlist = py27, py36, py37, py38, py39, py310, py311, pypy, pypy3, lint
+
+[testenv]
+commands = coverage run tests/tests.py
+basepython=
+    py27: python2.7
+    py36: python3.6
+    py37: python3.7
+    py38: python3.8
+    py39: python3.9
+    py310: python3.10
+    py311: python3.11
+    pypy: pypy
+    pypy3: pypy3
+    lint: python3.9
+deps =
+    coverage
+    importlib-metadata>=6.0.0
+download = True
+setenv =
+    pypy: VIRTUALENV_PIP=20.1.1
+    pypy: VIRTUALENV_DOWNLOAD=1
+
+[testenv:lint]
+commands = pycodestyle polib.py
+deps =
+    pycodestyle>=2.6.0