def METHOD_NAME(self):
    for sale in self:
        fsm = self.env["fsm.order"].search(
            [
                "|",
                ("sale_id", "=", sale.id),
                ("sale_line_id", "in", sale.order_line.ids),
            ]
        )
        sale.fsm_order_ids = fsm
        sale.fsm_order_count = len(sale.fsm_order_ids)