<PackageReference Include="NUnit" Version="4.5.1" />

NUnit.Framework.NUnitString

public struct NUnitString
A class to allow postponing the actual formatting of interpolated strings.
namespace NUnit.Framework { public readonly struct NUnitString { public NUnitString(string message); public static implicit operator NUnitString(FormattableString formattableMessage); public static implicit operator NUnitString(string message); } }