问“RestClient”不包含“JsonSerializer”的定义，也不包含扩展方法“JsonSerializer”

EN

*** IMPORTANT CHANGE IN RESTSHARP VERSION 103 ***

In 103.0, JSON.NET was removed as a dependency. 

If this is still installed in your project and no other libraries depend on 
it you may remove it from your installed packages.

There is one breaking change: the default Json*Serializer* is no longer 
compatible with Json.NET. To use Json.NET for serialization, copy the code 
from https://github.com/restsharp/RestSharp/blob/86b31f9adf049d7fb821de8279154f41a17b36f7/RestSharp/Serializers/JsonSerializer.cs 
and register it with your client:

var client = new RestClient();
client.JsonSerializer = new YourCustomSerializer();

The default Json*Deserializer* is mostly compatible, but it does not support
all features which Json.NET has (like the ability to support a custom [JsonConverter]
by decorating a certain property with an attribute). If you need these features, you
must take care of the deserialization yourself to get it working.

private void Form1_Load(object sender, EventArgs e)
        {        
            var client = new RestClient("http://homestead.app/vendor");
            client.JsonSerializer = new JsonSerializer(); <-- HERE IS THE ERROR
            var request = new RestRequest("", Method.GET);
            IRestResponse response = client.Execute(request);
            var content = response.Content; // raw content as string
            textBox1.Text = content;
        }