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: metadata.rs
    path of file: ./repos/sqlx/sqlx-cli/src
    
    the code of the file until where you have to start completion: use std::{
    collections::{btree_map, BTreeMap, BTreeSet},
    ffi::OsStr,
    path::{Path, PathBuf},
    process::Command,
    str::FromStr,
};

use anyhow::Context;
use cargo_metadata::{
    Metadata as CargoMetadata, Package as MetadataPackage, PackageId as MetadataId,
};

/// The minimal amount of package information we care about
///
/// The package's `name` is used to `cargo clean -p` specific crates while the `src_paths` are
/// are used to trigger recompiles of packages within the workspace
#[derive(Debug)]
pub struct Package {
    name: String,
    src_paths: Vec<PathBuf>,
}

impl Package {
    pub fn name(&self) -> &str {
        &self.name
    }

    pub fn src_paths(&self) -> &[PathBuf] {
        &self.src_paths
    }
}

impl From<&MetadataPackage> for Pack
    
    fn from_str(s: &str) -> Result<Self, Self::Err> {
        let cargo_metadata: CargoMetadata = serde_json::from_str(s)?;

        // Extract the package in the current working directory, empty if run from a
        // virtual workspace root.
        let current_package: Option<Package> = cargo_metadata.root_package().map(Package::from);

        let CargoMetadata {
            packages: metadata_packages,
            workspace_members,
            workspace_root,
            resolve,
            target_directory,
            ..
        } = cargo_metadata;

        let mut packages = BTreeMap::new();
        for metadata_package in metadata_packages {
            let package = Package::from(&metadata_package);
            packages.insert(metadata_package.id, package);
        }

        let mut reverse_deps: BTreeMap<_, BTreeSet<_>> = BTreeMap::new();
        let resolve =
            resolve.context("Resolving the dependency graph failed (old version of cargo)")?;
        for node in resolve.nodes {
            for dep in node.deps {
                let dependent = node.id.clone();
                let dependency = dep.pkg;
                reverse_deps
                    .entry(dependency)
                    .or_default()
                    .insert(dependent);
            }
        }

        let workspace_root = workspace_root.into_std_path_buf();
        let target_directory = target_directory.into_std_path_buf();

        Ok(Self {
            packages,
            workspace_members,
            workspace_root,
            reverse_deps,
            target_directory,
            current_package,
        })
    }