You are an expert in writing code in many different languages. Your goal is to perform code completion for the following code, keeping in mind the rest of the code and the file meta data.
    Metadata details:
    filename: generated_bearer_token_authenticator.rs
    path of file: ./repos/cnosdb/main/src/flight_sql/auth_middleware
    
    the code of the file until where you have to start completion: use std::time::Duration;

use http_protocol::header::BEARER_PREFIX;
use models::auth::user::User;
use models::oid::UuidGenerator;
use moka::sync::Cache;
use tonic::metadata::MetadataMap;
use tonic::Status;
use trace::debug;

use super::{AuthResult, CallHeaderA
    
    pub fn new(initial_authenticator: T) -> Self {
        let bearer_to_identifier = Cache::builder()
            .thread_pool_enabled(false)
            // Time to idle (TTL): 10 minutes
            // If bearer is not used within 10 minutes, it will expire
            .time_to_idle(Duration::from_secs(10 * 60))
            .build();

        Self {
            bearer_to_identifier,
            initial_authenticator,
            id_generator: Default::default(),
        }
    }