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: count.rs
    path of file: ./repos/mongo-rust-driver/src/test/spec/crud_v1
    
    the code of the file until where you have to start completion: use serde::Deserialize;

use super::{run_crud_v1_test, Outcome, TestFile};
use crate::{
    bson::{Bson, Document},
    options::{Collation, CountOptions},
    test::util::TestClient,
};

#[derive(Debug, Deserialize)]
struct Arguments {
    pub filter: Option<Document>,
    pub skip: Option<u64>,
    pub limit: Option<u64>,
    pub collation: Option<Collation>,
}

#[function_name::named]
async fn ru
    
async fn run_count_test(test_file: TestFile) {
    let client = TestClient::new().await;
    let data = test_file.data;

    for mut test_case in test_file.tests {
        let lower_description = test_case.description.to_lowercase();

        // old `count` not implemented, collation not implemented
        if !test_case.operation.name.contains("count") || lower_description.contains("deprecated") {
            continue;
        }

        test_case.description = test_case.description.replace('$', "%");

        let coll = client
            .init_db_and_coll(function_name!(), &test_case.description)
            .await;

        if !data.is_empty() {
            coll.insert_many(data.clone(), None)
                .await
                .expect(&test_case.description);
        }

        let arguments: Arguments = bson::from_bson(Bson::Document(test_case.operation.arguments))
            .expect(&test_case.description);
        let outcome: Outcome<u64> =
            bson::from_bson(Bson::Document(test_case.outcome)).expect(&test_case.description);

        if let Some(ref c) = outcome.collection {
            if let Some(ref name) = c.name {
                client.drop_collection(function_name!(), name).await;
            }
        }

        let result = match test_case.operation.name.as_str() {
            "countDocuments" => {
                let options = CountOptions::builder()
                    .skip(arguments.skip)
                    .limit(arguments.limit)
                    .collation(arguments.collation)
                    .build();
                coll.count_documents(arguments.filter.unwrap_or_default())
                    .with_options(options)
                    .await
            }
            "estimatedDocumentCount" => coll.estimated_document_count().await,
            other => panic!("unexpected count operation: {}", other),
        }
        .expect(&test_case.description);

        assert_eq!(result, outcome.result, "{}", test_case.description);
    }
}