<PackageReference Include="Polly.Core" Version="8.0.0-beta.2" />

NotNullWhenAttribute

Specifies that when a method returns ReturnValue, the parameter will not be null even if the corresponding type allows it.
namespace System.Diagnostics.CodeAnalysis { [AttributeUsage(AttributeTargets.Parameter, Inherited = false)] [ExcludeFromCodeCoverage] internal sealed class NotNullWhenAttribute : Attribute { public bool ReturnValue { get; } public NotNullWhenAttribute(bool returnValue) { ReturnValue = returnValue; } } }