use crate::db::{BufferId, ChannelId};use sea_orm::entity::prelude::*; #[derive(Clone, Debug, PartialEq, Eq, DeriveEntityModel)]#[sea_orm(table_name = "buffers")]pub struct Model {    #[sea_orm(primary_key)]    pub id: BufferId,    pub epoch: i32,    pub channel_id: ChannelId,    pub latest_operation_epoch: Option<i32>,    pub latest_operation_lamport_timestamp: Option<i32>,    pub latest_operation_replica_id: Option<i32>,} #[derive(Copy, Clone, Debug, EnumIter, DeriveRelation)]pub enum Relation {    #[sea_orm(has_many = "super::buffer_operation::Entity")]    Operations,    #[sea_orm(has_many = "super::buffer_snapshot::Entity")]    Snapshots,    #[sea_orm(        belongs_to = "super::channel::Entity",        from = "Column::ChannelId",        to = "super::channel::Column::Id"    )]    Channel,} impl Related<super::buffer_operation::Entity> for Entity {    fn to() -> RelationDef {        Relation::Operations.def()    }} impl Related<super::buffer_snapshot::Entity> for Entity {    fn to() -> RelationDef {        Relation::Snapshots.def()    }} impl Related<super::channel::Entity> for Entity {    fn to() -> RelationDef {        Relation::Channel.def()    }} impl ActiveModelBehavior for ActiveModel {}