Is SSR ID.unique() really unique?

import { Client, Databases, ID } from "appwrite";

const client = new Client()
    .setEndpoint('https://cloud.appwrite.io/v1')
    .setProject('<PROJECT_ID>');

const databases = new Databases(client);

const promise = databases.createDocument(
    '<DATABASE_ID>',
    '<COLLECTION_ID>',
    ID.unique(),
    { "title": "Hamlet" }
);

promise.then(function (response) {
    console.log(response);
}, function (error) {
    console.log(error);
});