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: mod.rs
    path of file: ./repos/meilisearch/dump/src/reader
    
    the code of the file until where you have to start completion: use std::fs::File;
use std::io::{BufReader, Read};

use flate2::bufread::GzDecoder;
use serde::Deserialize;
use tempfile::TempDir;

use self::compat::v4_to_v5::CompatV4ToV5;
use self::compat::v5_to_v6::{CompatIndexV5ToV6, CompatV5ToV6};
use self::v5::V5Reader;
use self::v6::{V6IndexReader, V6Reader};
use crate::{Result, Version};

mod compat;

mod v1;
mod v2;
mod v3;
mod v4;
mod v5;
mod v6;

pub type Document = serde_json::Map<String, serde_json::Value>;
pub type UpdateFile = dyn Iterator<Item = Result<Document>>;

pub enum DumpReader {
    Current(V6Reader),
    Compat(CompatV5ToV6),
}

impl DumpReader {
    pub fn open(dump: impl Read) -> Result<DumpReader> {
        let path = TempDir::new()?;
        let mut dump = BufReader::new(dump);
        let gz = GzDecoder::new(&mut dump);
        let mut archive = tar::Archive::new(gz);
        archive.unpack(path.path())?;

        #[derive(Deserialize)]
        #[serde(rename_all = "camelCase")]
        struct MetadataVersion {
            pub dump_version: Version,
        }
        let mut meta_file = File::open(path.path().join("metadata.json"))?;
        let MetadataVersion { dump_version } = serde_json::from_reader(&mut meta_file)?;

        match dump_version {
            Version::V1 => {
                Ok(v1::V1Reader::open(path)?.to_v2().to_v3().to_v4().to_v5().to_v6().into())
            }
            Version::V2 => Ok(v2::V2Reader::open(path)?.to_v3().to_v4().to_v5().to_v6().into()),
            Version::V3 => Ok(v3::V3Reader::open(path)?.to_v4().to_v5().to_v6().into()),
            Version::V4 => Ok(v4::V4Reader::open(path)?.to_v5().to_v6().into()),
            Version::V5 => Ok(v5::V5Reader::open(path)?.to_v6().into()),
            Version::V6 => Ok(v6::V6Reader::open(path)?.into()),
        }
    }

    pub fn version(&self) -> crate::Version {
        match self {
            DumpReader::Current(current) => current.version(),
            DumpReader::Compat(compat) => compat.version(),
        }
    }

    pub fn date(&self) -> Option<time::OffsetDateTime> {
        match self {
            DumpReader::Current(current) => current.date(),
            DumpReader::Compat(compat) => compat.date(),
        }
    }

    pub fn instance_uid(&self) -> Result<Option<uuid::Uuid>> {
        match self {
            DumpReader::Current(current) => current.instance_uid(),
            DumpReader::Compat(compat) => compat.instance_uid(),
        }
    }

    pub fn indexes(&self) -> Result<Box<dyn Iterator<Item = Result<DumpIndexReader>> + '_>> {
        match self {
            DumpReader::Current(current) => {
                let indexes = Box::new(current.indexes()?.map(|res| res.map(DumpIndexReader::from)))
                    as Box<dyn Iterator<Item = Result<DumpIndexReader>> + '_>;
                Ok(indexes)
            }
            DumpReader::Compat(compat) => {
                let indexes = Box::new(compat.indexes()?.map(|res| res.map(DumpIndexReader::from)))
                    as Box<dyn Iterator<Item = Result<DumpIndexReader>> + '_>;
                Ok(indexes)
            }
        }
    }

    pub fn tasks(
        &mut self,
    ) -> Result<Box<dyn Iterator<Item = Result<(v6::Task, Option<Box<UpdateFile>>)>> + '_>> {
        match self {
            DumpReader::Current(current) => Ok(current.tasks()),
            DumpReader::Compat(compat) => compat.tasks(),
        }
    }

    pub fn keys(&mut self) -> Result<Box<dyn Iter
    
    fn import_dump_v3() {
        let dump = File::open("tests/assets/v3.dump").unwrap();
        let mut dump = DumpReader::open(dump).unwrap();

        // top level infos
        insta::assert_display_snapshot!(dump.date().unwrap(), @"2022-10-07 11:39:03.709153554 +00:00:00");
        assert_eq!(dump.instance_uid().unwrap(), None);

        // tasks
        let tasks = dump.tasks().unwrap().collect::<Result<Vec<_>>>().unwrap();
        let (tasks, update_files): (Vec<_>, Vec<_>) = tasks.into_iter().unzip();
        meili_snap::snapshot_hash!(meili_snap::json_string!(tasks), @"cd12efd308fe3ed226356a727ab42ed3");
        assert_eq!(update_files.len(), 10);
        assert!(update_files[0].is_some()); // the enqueued document addition
        assert!(update_files[1..].iter().all(|u| u.is_none())); // everything already processed

        // keys
        let keys = dump.keys().unwrap().collect::<Result<Vec<_>>>().unwrap();
        meili_snap::snapshot_hash!(meili_snap::json_string!(keys), @"d751713988987e9331980363e24189ce");

        // indexes
        let mut indexes = dump.indexes().unwrap().collect::<Result<Vec<_>>>().unwrap();
        // the index are not ordered in any way by default
        indexes.sort_by_key(|index| index.metadata().uid.to_string());

        let mut products = indexes.pop().unwrap();
        let mut movies2 = indexes.pop().unwrap();
        let mut movies = indexes.pop().unwrap();
        let mut spells = indexes.pop().unwrap();
        assert!(indexes.is_empty());

        // products
        insta::assert_json_snapshot!(products.metadata(), { ".createdAt" => "[now]", ".updatedAt" => "[now]" }, @r###"
        {
          "uid": "products",
          "primaryKey": "sku",
          "createdAt": "[now]",
          "updatedAt": "[now]"
        }
        "###);

        insta::assert_json_snapshot!(products.settings().unwrap());
        let documents = products.documents().unwrap().collect::<Result<Vec<_>>>().unwrap();
        assert_eq!(documents.len(), 10);
        meili_snap::snapshot_hash!(format!("{:#?}", documents), @"548284a84de510f71e88e6cdea495cf5");

        // movies
        insta::assert_json_snapshot!(movies.metadata(), { ".createdAt" => "[now]", ".updatedAt" => "[now]" }, @r###"
        {
          "uid": "movies",
          "primaryKey": "id",
          "createdAt": "[now]",
          "updatedAt": "[now]"
        }
        "###);

        insta::assert_json_snapshot!(movies.settings().unwrap());
        let documents = movies.documents().unwrap().collect::<Result<Vec<_>>>().unwrap();
        assert_eq!(documents.len(), 110);
        meili_snap::snapshot_hash!(format!("{:#?}", documents), @"d153b5a81d8b3cdcbe1dec270b574022");

        // movies2
        insta::assert_json_snapshot!(movies2.metadata(), { ".createdAt" => "[now]", ".updatedAt" => "[now]" }, @r###"
        {
          "uid": "movies_2",
          "primaryKey": null,
          "createdAt": "[now]",
          "updatedAt": "[now]"
        }
        "###);

        insta::assert_json_snapshot!(movies2.settings().unwrap());
        let documents = movies2.documents().unwrap().collect::<Result<Vec<_>>>().unwrap();
        assert_eq!(documents.len(), 0);
        meili_snap::snapshot_hash!(format!("{:#?}", documents), @"d751713988987e9331980363e24189ce");

        // spells
        insta::assert_json_snapshot!(spells.metadata(), { ".createdAt" => "[now]", ".updatedAt" => "[now]" }, @r###"
        {
          "uid": "dnd_spells",
          "primaryKey": "index",
          "createdAt": "[now]",
          "updatedAt": "[now]"
        }
        "###);

        insta::assert_json_snapshot!(spells.settings().unwrap());
        let documents = spells.documents().unwrap().collect::<Result<Vec<_>>>().unwrap();
        assert_eq!(documents.len(), 10);
        meili_snap::snapshot_hash!(format!("{:#?}", documents), @"235016433dd04262c7f2da01d1e808ce");
    }