def METHOD_NAME(cls, slc: Slice) -> Slice:
    form_data = try_load_json(slc.params)
    if "viz_type" in (form_data_bak := form_data.get(FORM_DATA_BAK_FIELD_NAME, {})):
        slc.params = json.dumps(form_data_bak)
        slc.viz_type = form_data_bak.get("viz_type")
        query_context = try_load_json(slc.query_context)
        if "form_data" in query_context:
            query_context["form_data"] = form_data_bak
            slc.query_context = json.dumps(query_context)
    return slc