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: config.rs
    path of file: ./repos/spotifyd/src
    
    the code of the file until where you have to start completion: use crate::{
    error::{Error as CrateError, ParseError},
    process::run_program,
    utils,
};
use color_eyre::Report;
use gethostname::gethostname;
use librespot_core::{
    cache::Cache, config::DeviceType as LSDeviceType, config::SessionConfig, version,
};
use librespot_playback::config::{
    AudioFormat as LSAudioFormat, Bitrate as LSBitrate, PlayerConfig,
};
use log::{error, info, warn};
use serde::{de::Error, de::Unexpected, Deserialize, Deserializer};
use sha1::{Digest, Sha1};
use std::{fmt, fs, path::Path, path::PathBuf, str::FromStr, string::ToString};
use structopt::{clap::AppSettings, StructOpt};
use url::Url;

const CONFIG_FILE_NAME: &str = "spotifyd.conf";

#[cfg(not(any(
    feature = "pulseaudio_backend",
    feature = "portaudio_backend",
    feature = "alsa_backend",
    feature = "rodio_backend"
)))]

    
    pub fn merge_with(&mut self, other: SharedConfigValues) {
        macro_rules! merge {
            ($($x:ident),+) => {
                $(self.$x = self.$x.clone().or_else(|| other.$x.clone());)+
            }
        }

        // Handles Option<T> merging.
        merge!(
            backend,
            username,
            username_cmd,
            password,
            password_cmd,
            normalisation_pregain,
            bitrate,
            initial_volume,
            device_name,
            mixer,
            control,
            device,
            volume_controller,
            cache_path,
            on_song_change_hook,
            zeroconf_port,
            proxy,
            device_type,
            use_mpris,
            max_cache_size,
            dbus_type,
            audio_format
        );

        // Handles boolean merging.
        self.use_keyring |= other.use_keyring;
        self.volume_normalisation |= other.volume_normalisation;
        self.no_audio_cache |= other.no_audio_cache;
        self.autoplay |= other.autoplay;
    }