<PackageReference Include="System.Text.Json" Version="6.0.9" />

MemberNotNullAttribute

Specifies that the method or property will ensure that the listed field and property members have not-null values.
namespace System.Diagnostics.CodeAnalysis { [AttributeUsage(AttributeTargets.Method | AttributeTargets.Property, Inherited = false, AllowMultiple = true)] internal sealed class MemberNotNullAttribute : Attribute { public string[] Members { get; } public MemberNotNullAttribute(string member) { Members = new string[1] { member }; } public MemberNotNullAttribute(params string[] members) { Members = members; } } }