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: rfcs.rs
    path of file: ./repos/rust-search-extension/rust/src/tasks
    
    the code of the file until where you have to start completion: use std::{fs, path::Path};

use super::Task;
use argh::FromArgs;
use rayon::slice::ParallelSliceMut;
use serde::{Deserialize, Serialize};

const INDEX_PATH: &str = "../extension/index/rfcs.js";

/// Rfc-index task
#[derive(FromArgs)]
#[argh(subcommand, name = "rfcs")]
pub struct RfcsTask {
    /// rfc-index repository path
    #[argh(option, short = '
    
    fn execute(&self) -> crate::Result<()> {
        let mut data_dir = Path::new(&self.repo_path).to_path_buf();
        data_dir.push("metadata");
        let mut metadatas = vec![];
        for entry in fs::read_dir(data_dir)? {
            let file = entry?;
            if file.file_name() == "tags.json" {
                continue;
            }

            let metadata = serde_json::from_str::<RfcMetadata>(&fs::read_to_string(file.path())?)?;
            metadatas.push(metadata.into_tuple());
        }

        metadatas.par_sort_by(|a, b| a.0.cmp(&b.0));

        let path = Path::new(&self.dest_path);
        fs::write(
            path,
            format!("var rfcsIndex={};", serde_json::to_string(&metadatas)?),
        )?;

        Ok(())
    }