def timer_nav(context):
    """
    Get a list of Timer instances to include in the nav menu.
    :param context: Django's context data.
    :returns: a dictionary with timers data.
    """
    request = context["request"] or None
    timers = Timer.objects.filter()
    children = Child.objects.all()
    perms = context["perms"] or None
    # The 'next' parameter is currently not used.
    return {
        "timers": timers,
        "children": children,
        "perms": perms,
        "next": request.path,
    }

    Get a list of Timer instances to include in the nav menu.
    :param context: Django's context data.
    :returns: a dictionary with timers data.
    
core/templatetags/timers.py