def worker_process_control(_destination, _destination_process_id, _command, _reason, _message_id, _source,
                           _source_process_id, _user_id):
    """
    Creates a worker process control message. Tells a worker process to stop, kill, etcetera.
    """
    return {
        "destination": _destination,
        "destinationProcessId": _destination_process_id,
        "command": _command,
        "reason": _reason,
        "messageId": _message_id,
        "source": _source,
        "sourceProcessId": _source_process_id,
        "userId": _user_id,
        "schemaRef": "ref://bpm.message.worker.process.command"
    }