use serde::{Deserialize, Serialize};use std::fmt::{self, Display}; #[derive(Clone, Copy, Serialize, Deserialize, Debug, Eq, PartialEq, Hash)]#[serde(rename_all = "lowercase")]pub enum Role {    User,    Assistant,    System,} impl Role {    pub fn from_proto(role: i32) -> Role {        match proto::LanguageModelRole::from_i32(role) {            Some(proto::LanguageModelRole::LanguageModelUser) => Role::User,            Some(proto::LanguageModelRole::LanguageModelAssistant) => Role::Assistant,            Some(proto::LanguageModelRole::LanguageModelSystem) => Role::System,            None => Role::User,        }    }     pub fn to_proto(self) -> proto::LanguageModelRole {        match self {            Role::User => proto::LanguageModelRole::LanguageModelUser,            Role::Assistant => proto::LanguageModelRole::LanguageModelAssistant,            Role::System => proto::LanguageModelRole::LanguageModelSystem,        }    }     pub fn cycle(self) -> Role {        match self {            Role::User => Role::Assistant,            Role::Assistant => Role::System,            Role::System => Role::User,        }    }} impl Display for Role {    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> std::fmt::Result {        match self {            Role::User => write!(f, "user"),            Role::Assistant => write!(f, "assistant"),            Role::System => write!(f, "system"),        }    }}