The code is 3-clause BSD licensed now.

src/allmydata/test/_win_subprocess.py

@@ -1,3 +1,37 @@
+# -*- coding: utf-8 -*-
+
+## Copyright (C) 2021 Valentin Lab
+##
+## Redistribution and use in source and binary forms, with or without
+## modification, are permitted provided that the following conditions
+## are met:
+##
+## 1. Redistributions of source code must retain the above copyright
+## notice, this list of conditions and the following disclaimer.
+##
+## 2. Redistributions in binary form must reproduce the above
+## copyright notice, this list of conditions and the following
+## disclaimer in the documentation and/or other materials provided
+## with the distribution.
+##
+## 3. Neither the name of the copyright holder nor the names of its
+## contributors may be used to endorse or promote products derived
+## from this software without specific prior written permission.
+##
+## THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+## "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+## LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
+## FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
+## COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT,
+## INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
+## (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
+## SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+## HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
+## STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
+## ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
+## OF THE POSSIBILITY OF SUCH DAMAGE.
+##
+
 ## issue: https://bugs.python.org/issue19264
 
 import os