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: task_local.rs
    path of file: ./repos/async-std/src/task
    
    the code of the file until where you have to start completion: use std::cell::UnsafeCell;
use std::error::Error;
use std::fmt;
use std::sync::atomic::{AtomicU32, Ordering};

use crate::task::TaskLocalsWrapper;

/// The key for accessing a task-local value.
///
/// Every task-local value is lazily initialized on first access and destroyed when the task
/// comp
    
    fn key(&self) -> u32 {
        #[cold]
        fn init(key: &AtomicU32) -> u32 {
            static COUNTER: AtomicU32 = AtomicU32::new(1);

            let counter = COUNTER.fetch_add(1, Ordering::Relaxed);
            if counter > u32::max_value() / 2 {
                std::process::abort();
            }

            match key.compare_exchange(0, counter, Ordering::AcqRel, Ordering::Acquire) {
                Ok(_) => counter,
                Err(k) => k,
            }
        }

        match self.__key.load(Ordering::Acquire) {
            0 => init(&self.__key),
            k => k,
        }
    }