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: fetch.rs
    path of file: ./repos/cargo-edit/src
    
    the code of the file until where you have to start completion: use std::collections::BTreeMap;
use std::path::Path;
use std::time::Duration;

use url::Url;

use super::errors::*;
use super::registry::registry_url;
use super::shell_status;
use super::Dependency;
use super::RegistrySource;
use super::VersionExt;

/// Query latest version from a registry index
///
/// The registry argument must be specified for crates
/// from alternative registries.
///
/// The latest version will be returned as a `Dependency`. This will fail, when
///
/// - th
    
fn gen_fuzzy_crate_names(crate_name: String) -> CargoResult<Vec<String>> {
    const PATTERN: [u8; 2] = [b'-', b'_'];

    let wildcard_indexs = crate_name
        .bytes()
        .enumerate()
        .filter(|(_, item)| PATTERN.contains(item))
        .map(|(index, _)| index)
        .take(10)
        .collect::<Vec<usize>>();
    if wildcard_indexs.is_empty() {
        return Ok(vec![crate_name]);
    }

    let mut result = vec![];
    let mut bytes = crate_name.into_bytes();
    for mask in 0..2u128.pow(wildcard_indexs.len() as u32) {
        for (mask_index, wildcard_index) in wildcard_indexs.iter().enumerate() {
            let mask_value = (mask >> mask_index) & 1 == 1;
            if mask_value {
                bytes[*wildcard_index] = b'-';
            } else {
                bytes[*wildcard_index] = b'_';
            }
        }
        result.push(String::from_utf8(bytes.clone()).unwrap());
    }
    Ok(result)
}