How to use the vscode-azureextensionui.appendExtensionUserAgent function in vscode-azureextensionui

export async function parseMongoConnectionString(connectionString: string): Promise {
    let host: string;
    let port: string;

    const mongoClient: MongoClient = await connectToMongoClient(connectionString, appendExtensionUserAgent());
    const serverConfig: Server | ReplSet | Mongos = mongoClient.db(testDb).serverConfig;
    // Azure CosmosDB comes back as a ReplSet
    if (serverConfig instanceof ReplSet) {
        // get the first connection string from the servers for the ReplSet
        // this may not be best solution, but the connection (below) gives
        // the replicaset host name, which is different than what is in the connection string
        // "s" is not part of ReplSet static definition but can't find any official documentation on it. Yet it is definitely there at runtime. Grandfathering in.
        // tslint:disable-next-line:no-any
        let rs: any = serverConfig;
        host = rs.s.options.servers[0].host;
        port = rs.s.options.servers[0].port;
    } else {
        host = serverConfig['host'];
        port = serverConfig['port'];
    }

public async loadMoreChildrenImpl(_clearCache: boolean): Promise[]> {
        let mongoClient: MongoClient | undefined;
        try {
            let databases: IDatabaseInfo[];

            if (!this.connectionString) {
                throw new Error('Missing connection string');
            }

            // Azure MongoDB accounts need to have the name passed in for private endpoints
            mongoClient = await connectToMongoClient(this.connectionString, this.databaseAccount ? this.databaseAccount.name : appendExtensionUserAgent());

            let databaseInConnectionString = getDatabaseNameFromConnectionString(this.connectionString);
            if (databaseInConnectionString && !this.root.isEmulator) { // emulator violates the connection string format
                // If the database is in the connection string, that's all we connect to (we might not even have permissions to list databases)
                databases = [{
                    name: databaseInConnectionString,
                    empty: false
                }];
            } else {
                // https://mongodb.github.io/node-mongodb-native/3.1/api/index.html
                let result: { databases: IDatabaseInfo[] } = await mongoClient.db(testDb).admin().listDatabases();
                databases = result.databases;
            }
            return databases
                .filter((database: IDatabaseInfo) => !(database.name && database.name.toLowerCase() === "admin" && database.empty)) // Filter out the 'admin' database if it's empty
                .map(database => new MongoDatabaseTreeItem(this, database.name, this.connectionString));

public async connectToDb(): Promise {
		const accountConnection = await connectToMongoClient(this.connectionString, appendExtensionUserAgent());
		return accountConnection.db(this.databaseName);
	}