Newtonsoft.Json by James Newton-King

<PackageReference Include="Newtonsoft.Json" Version="10.0.3" />

 DefaultValueHandling

public enum DefaultValueHandling
Specifies default value handling options for the JsonSerializer.
using System; namespace Newtonsoft.Json { [Flags] public enum DefaultValueHandling { Include = 0, Ignore = 1, Populate = 2, IgnoreAndPopulate = 3 } }