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: toolchain.rs
    path of file: ./repos/risc0/risc0/cargo-risczero/src
    
    the code of the file until where you have to start completion: // Copyright 2024 RISC Zero, Inc.
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// Y
    
    pub fn link(name: &str, dir: &Path) -> Result<Self> {
        eprintln!(
            "Activating rustup toolchain {} at {}...",
            name,
            dir.display()
        );

        // Small sanity check.
        #[cfg(not(target_os = "windows"))]
        let rustc_exe = "rustc";
        #[cfg(target_os = "windows")]
        let rustc_exe = "rustc.exe";

        let rustc_path = dir.join("bin").join(rustc_exe);
        if !rustc_path.is_file() {
            bail!(
                "Invalid toolchain directory: rustc executable not found at {}",
                rustc_path.display()
            );
        }

        // If already present, unlink first.
        // This is required because otherwise rustup can get in a buggy state.
        if Self::find_by_name(name)?.is_some() {
            Command::new("rustup")
                .args(["toolchain", "remove", name])
                .run()
                .context("Could not remove existing toolchain")?;
        }

        Command::new("rustup")
            .args(["toolchain", "link", name])
            .arg(dir)
            .run_verbose()
            .context("Could not link toolchain: rustup not installed?")?;

        eprintln!("rustup toolchain {name} was linked and is now available!");

        Ok(Self {
            name: name.to_string(),
            path: dir.into(),
        })
    }