Number type (u16) field of struct throwing "invalid type: floating point `21010`, expected u16" about bson-rust HOT 2 CLOSED

use bson::doc;
use mongodb::options::FindOptions;
use serde::{Serialize, Deserialize};
use futures::stream::TryStreamExt;

#[derive(Debug, Serialize, Deserialize)]
struct Book {
    title: String,
    author: String,
    problem: u16,
}

#[tokio::main]
async fn main() {
    let book = Book {
        title: "1984".to_string(),
        author: "George Orwell".to_string(),
        problem: 21010,
    };
    println!("original book:    {:?}", book);
    let bson_roundtrip: Book = bson::from_bson(bson::to_bson(&book).unwrap()).unwrap();
    println!("bson roundtrip:   {:?}", bson_roundtrip);
    let binary_roundtrip: Book = bson::from_reader(bson::to_vec(&book).unwrap().as_slice()).unwrap();
    println!("binary roundtrip: {:?}", binary_roundtrip);

    let client = mongodb::Client::with_uri_str("mongodb://localhost:27017").await.unwrap();
    let typed_collection = client.database("test_u16").collection::<Book>("test");
    typed_collection.drop(None).await.unwrap();
    typed_collection.insert_one(&book, None).await.unwrap();

    // Query the books in the collection with a filter and an option.
    let filter = doc! { "author": "George Orwell" };
    let find_options = FindOptions::builder().sort(doc! { "title": 1 }).build();
    let mut cursor = typed_collection.find(filter, find_options).await.unwrap();

    // Iterate over the results of the cursor.
    while let Some(book) = cursor.try_next().await.unwrap() {
        println!("title: {}", book.title);
    }
}