<PackageReference Include="System.ClientModel" Version="1.15.0" />

System.Diagnostics.CodeAnalysis.NotNullAttribute

sealed class NotNullAttribute : Attribute
namespace System.Diagnostics.CodeAnalysis { } namespace System.Diagnostics.CodeAnalysis { } namespace System.Diagnostics.CodeAnalysis { internal sealed class NotNullAttribute : Attribute { public NotNullAttribute(); } }