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: data.rs
    path of file: ./repos/crates.io/crates/crates_io_index
    
    the code of the file until where you have to start completion: use std::cmp::Ordering;
use std::collections::BTreeMap;

#[derive(Serialize, Deserialize, Debug)]
pub struct Crate {
    pub name: String,
    pub vers: String,
    pub deps: Vec<Dependency>,
    pub cksum: String,
    pub features: BTreeMap<String, Vec<String>>,
    /// This field contains features with new, extended syntax. Specifically,
    /// namespaced features (`dep:`) and weak dependencies (`pkg?/feat`).
    ///
    /// It is only populated if a feature uses the new syntax. Cargo merges it
    /// on to
    
    fn cmp(&self, other: &Self) -> Ordering {
        // In old `cargo` versions the dependency order appears to matter if the
        // same dependency exists twice but with different `kind` fields. In
        // those cases the `optional` field can sometimes be ignored or
        // misinterpreted. With this manual `Ord` implementation we ensure that
        // `normal` dependencies are always first when multiple with the same
        // `name` exist.
        (
            &self.name,
            self.kind,
            &self.req,
            self.optional,
            self.default_features,
            &self.target,
            &self.package,
            &self.features,
        )
            .cmp(&(
                &other.name,
                other.kind,
                &other.req,
                other.optional,
                other.default_features,
                &other.target,
                &other.package,
                &other.features,
            ))
    }