<PackageReference Include="NUnit" Version="3.7.0" />

IConstraint

public interface IConstraint : IResolveConstraint
Interface for all constraints
namespace NUnit.Framework.Constraints { public interface IConstraint : IResolveConstraint { string DisplayName { get; } string Description { get; } object[] Arguments { get; } ConstraintBuilder Builder { get; set; } ConstraintResult ApplyTo<TActual>(TActual actual); ConstraintResult ApplyTo<TActual>(ActualValueDelegate<TActual> del); ConstraintResult ApplyTo<TActual>(ref TActual actual); } }