狂饮不发送自定义标题

Question

我尝试随请求发送自定义标头，但不断发送默认标头。

这是GuzzleClient我的代码中的创建

$httpClient = new \GuzzleHttp\Client( [
            'headers' => [
                ['Accept' => ' text/html,application/xhtml+xml,application/xml;q=0.9,image/webp,*/*;q=0.8'],
                ['Accept-Language' => 'en-US,en;q=0.5'],
                ['Upgrade-Insecure-Requests' => '1'],
                ['User-Agent'      => 'Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/70.0.3538.77 Safari/537.36'],
                ['Accept-Encoding' => 'gzip, deflate, br']
            ]
        ] );

但是我看到默认的标题（用户代理：Guzzle）

我的代码有什么问题