<PackageReference Include="System.Text.Json" Version="11.0.0-preview.2.26159.112" />

System.Text.Json.Serialization.JsonIncludeAttribute

public sealed class JsonIncludeAttribute : JsonAttribute
Indicates that the member should be included for serialization and deserialization.
namespace System.Text.Json.Serialization { public sealed class JsonIncludeAttribute : JsonAttribute { public JsonIncludeAttribute(); } }