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: metrics.rs
    path of file: ./repos/arroyo/arroyo-api/src
    
    the code of the file until where you have to start completion: use axum::extract::{Path, State};
use axum::Json;
use base64::engine::general_purpose;
use base64::Engine;
use std::str::FromStr;
use std::{collections::HashMap, env, time::SystemTime};

use crate::pipelines::query_job_by_pub_id;
use crate::rest::AppState;
use crate::rest_utils
    
fn backpressure_query(job_id: &str, run_id: &u64) -> String {
    let tx_queue_size: String = format!(
        "{}{{job_id=\"{}\",run_id=\"{}\"}}",
        TX_QUEUE_SIZE, job_id, run_id
    );
    let tx_queue_rem: String = format!(
        "{}{{job_id=\"{}\",run_id=\"{}\"}}",
        TX_QUEUE_REM, job_id, run_id
    );
    // add 1 to each value to account for uninitialized values (which report 0); this can happen when a task
    // never reads any data
    format!("1 - (({} + 1) / ({} + 1))", tx_queue_rem, tx_queue_size)
}