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/exonum/components/merkledb
    
    the code of the file until where you have to start completion: // Copyright 2020 The Exonum Team
//
// Licensed under the Apach
    
fn gen_proto_files() {
    use exonum_build::ProtobufGenerator;
    use std::env;

    let current_dir = env::current_dir().expect("Failed to get current dir.");
    let protos = current_dir.join("src/proto");
    println!("cargo:protos={}", protos.to_str().unwrap());

    ProtobufGenerator::with_mod_name("protobuf_mod.rs")
        .with_input_dir("src/proto")
        .with_crypto()
        .generate();
}