def __init__(self, uid=None, gid=None):
        """
        Set uid and gid.

        @param uid: The user ID as whom to execute the process.  If
            this is L{None}, no attempt will be made to change the UID.

        @param gid: The group ID as whom to execute the process.  If
            this is L{None}, no attempt will be made to change the GID.
        """
        self.uid = uid
        self.gid = gid

        Set uid and gid.

        @param uid: The user ID as whom to execute the process.  If
            this is L{None}, no attempt will be made to change the UID.

        @param gid: The group ID as whom to execute the process.  If
            this is L{None}, no attempt will be made to change the GID.
        
stackoverflow/venv/lib/python3.6/site-packages/twisted/application/service.py