The usage of map looks like array , not map, why this way please?

[videni]

Swift

 var document: YDocument!
    var map: YMap<TestType>!

    override func setUp() {
        document = YDocument()
        map = document.getOrCreateMap(named: "test")
    }

    override func tearDown() {
        document = nil
        map = nil
    }

    func test_insert() {
        let initialInstance = TestType(name: "Aidar", age: 24)
        let secondInstance = TestType(name: "Joe", age: 55)

// the map looks like an array?
        XCTAssertEqual(map.length(), 0)
        map[initialInstance.name] = initialInstance
        map[secondInstance.name] = secondInstance
        XCTAssertEqual(map.length(), 2)

        let finalInstance = map.get(key: initialInstance.name)

        XCTAssertEqual(initialInstance, finalInstance)

        let contains = map.containsKey(secondInstance.name)
        XCTAssertTrue(contains)
    }

Rust

use yrs::{any, Array, ArrayPrelim, Doc, In, JsonPath, JsonPathEval, Map, MapPrelim, Out, Transact, WriteTxn};

let doc = Doc::new();
let mut txn = doc.transact_mut();
let users = txn.get_or_insert_array("users");

// here is  a  map in an array

users.insert(&mut txn, 0, MapPrelim::from([
    ("name".to_string(), In::Any(any!("Alice"))),
    ("surname".into(), In::Any(any!("Smith"))),
    ("age".into(), In::Any(any!(25))),
    (
        "friends".into(),
        In::from(ArrayPrelim::from([
            any!({ "name": "Bob", "nick": "boreas" }),
            any!({ "nick": "crocodile91" }),
        ])),
    ),
]));