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: prost.rs
    path of file: ./repos/tonic/tonic-build/src
    
    the code of the file until where you have to start completion: use crate::{code_gen::CodeGenBuilder, compile_settings::CompileSettings};

use super::Attributes;
use proc_macro2::TokenStream;
use prost_build::{Config, Method, Service};
use quote::ToTokens;
use std::{
    collections::HashSet,
    ffi::OsString,
    io,
    path::{Path, PathBuf},
};

/// Configure `tonic-build` code generation.
///
/// Use [`compile_protos`] instead if you don't need to tweak anything.
pub fn configure() -> Builder {
    Builder {
        build_client: tr
    
    fn finalize(&mut self, buf: &mut String) {
        if self.builder.build_client && !self.clients.is_empty() {
            let clients = &self.clients;

            let client_service = quote::quote! {
                #clients
            };

            let ast: syn::File = syn::parse2(client_service).expect("not a valid tokenstream");
            let code = prettyplease::unparse(&ast);
            buf.push_str(&code);

            self.clients = TokenStream::default();
        }

        if self.builder.build_server && !self.servers.is_empty() {
            let servers = &self.servers;

            let server_service = quote::quote! {
                #servers
            };

            let ast: syn::File = syn::parse2(server_service).expect("not a valid tokenstream");
            let code = prettyplease::unparse(&ast);
            buf.push_str(&code);

            self.servers = TokenStream::default();
        }
    }