Multi Select Dialog - Retun all rows when the param that given to Filter is empty


I am trying to use Multi Select Dialog to get some records by giving the filter 2 parameters .
How can I get all record if the given parameters were empty?

    var d =   new frappe.ui.form.MultiSelectDialog({
          doctype: "Cheque",
          target: me.frm,
          setters: {
            cheque_no: "",
            cheque_value_date: "",
          date_field: "cheque_value_date",
          get_query() {
              return {
                  filters: {
                     cheque_status: ['=', ch_status],
                     current_account: ['=', vr_account]