<PackageReference Include="Newtonsoft.Json" Version="13.0.2" />

Newtonsoft.Json.Serialization.ExtensionDataSetter

public sealed delegate ExtensionDataSetter : MulticastDelegate
Sets extension data for an object during deserialization.
namespace Newtonsoft.Json.Serialization { public delegate void ExtensionDataSetter (object o, string key, object value); }