在我的提供程序中使用来自lodash的_.first函数？

Question

我有提供者，其参数为$ scope和HTMLElement。我使用.find在CSS中查找元素，我想从CSS中推入第一个参数。

我的有效代码

[INFO] Building new asset graph completed, took 2.3s
[INFO] Checking for unexpected pre-existing outputs. completed, took 1ms
[INFO] Serving `web` on http://127.0.0.1:8081
[SEVERE] ERROR - 2019-09-12 09:19:11.608930
[SEVERE] Asynchronous error
[SEVERE] type '_WebSocketProtocolTransformer' is not a subtype of type 'StreamTransformer<Uint8List, dynamic>' of 'streamTransformer'
[SEVERE] dart:async                                                       Stream.transform
[SEVERE] package:web_socket_channel/src/copy/web_socket_impl.dart 712:28  new WebSocketImpl.fromSocket
[SEVERE] package:web_socket_channel/src/channel.dart 94:36                new WebSocketChannel
[SEVERE] package:shelf_web_socket/src/web_socket_handler.dart 82:15       WebSocketHandler.handle.<fn>
[SEVERE] 

我必须使用_.first（）之类的东西吗？

new GoogleProvider(this.$scope, this.$element.find('.map-container')[0], () => {
                this.onMapReady()
            })