def initializeEnvironment(self, count, pid):
        """
        Create a copy of the process environment and add I{LISTEN_FDS} and
        I{LISTEN_PID} (the environment variables set by systemd) to it.
        """
        result = os.environ.copy()
        result['LISTEN_FDS'] = str(count)
        result['LISTEN_PID'] = str(pid)
        return result

        Create a copy of the process environment and add I{LISTEN_FDS} and
        I{LISTEN_PID} (the environment variables set by systemd) to it.
        
stackoverflow/venv/lib/python3.6/site-packages/twisted/python/test/test_systemd.py