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: index_part.rs
    path of file: ./repos/neon/pageserver/ctl/src
    
    the code of the file until where you have to start completion: use std::collections::HashMap;

use anyhow::Context;
use camino::Utf8PathBuf;
use pageserver::tenant::remote_timeline_client::index::IndexLayerMetadata;
use pageserver::tenant::storage_layer::LayerFile
    
pub(crate) async fn main(cmd: &IndexPartCmd) -> anyhow::Result<()> {
    match cmd {
        IndexPartCmd::Dump { path } => {
            let bytes = tokio::fs::read(path).await.context("read file")?;
            let des: IndexPart = IndexPart::from_s3_bytes(&bytes).context("deserialize")?;
            #[derive(serde::Serialize)]
            struct Output<'a> {
                layer_metadata: &'a HashMap<LayerFileName, IndexLayerMetadata>,
                disk_consistent_lsn: Lsn,
                timeline_metadata: &'a TimelineMetadata,
            }

            let output = Output {
                layer_metadata: &des.layer_metadata,
                disk_consistent_lsn: des.get_disk_consistent_lsn(),
                timeline_metadata: &des.metadata,
            };

            let output = serde_json::to_string_pretty(&output).context("serialize output")?;
            println!("{output}");
            Ok(())
        }
    }
}