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: build.rs
    path of file: ./repos/CYFS/src/component/cyfs-backup
    
    the code of the file until where you have to start completion: use std::io::Write;

static MOD_PROTOS_RS: &str = r#"
pub mod backup_objects;
mod backup_objects_with_macro;

pub use backup_objects_with_macro::*;
"#;

fn gen_protos() {
    let mut gen = protoc_rust::Codegen::new();
    let out_dir = std::env::var("OUT_DIR").unwrap();
    gen.input("protos/backup_objects.proto")
    .protoc_path(protoc_bin_vendored::protoc_bin_path().unwrap())
   
    
fn gen_protos() {
    let mut gen = protoc_rust::Codegen::new();
    let out_dir = std::env::var("OUT_DIR").unwrap();
    gen.input("protos/backup_objects.proto")
    .protoc_path(protoc_bin_vendored::protoc_bin_path().unwrap())
        .out_dir(&out_dir)
        .customize(protoc_rust::Customize {
            expose_fields: Some(true),
            ..Default::default()
        });

    gen.run().expect("protoc backup_objects error!");

    let mut config = prost_build::Config::new();
    config.default_package_filename("backup_objects_with_macro");
    config
        .compile_protos(&["protos/backup_objects.proto"], &["protos"])
        .unwrap();

    std::fs::File::create(out_dir + "/mod.rs").expect("write protos mod error")
        .write_all(MOD_PROTOS_RS.as_ref()).expect("write protos mod error");
}