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: resolve.rs
    path of file: ./repos/pixi/src/lock_file
    
    the code of the file until where you have to start completion: //! This module contains code to resolve python package from PyPi or Conda packages.
//!
//! See [`resolve_pypi`] and [`resolve_conda`] for more information.

use crate::config::get_cache_dir;
use crate
    
fn single_version_requirement(name: PackageName, version: Version) -> Requirement {
    Requirement {
        name,
        version_or_url: Some(pep508_rs::VersionOrUrl::VersionSpecifier(
            [
                VersionSpecifier::new(Operator::Equal, VersionPattern::verbatim(version))
                    .expect("this should always work"),
            ]
            .into_iter()
            .collect(),
        )),
        extras: Vec::default(),
        marker: None,
    }
}