namespace NUnit.Framework.Constraints { public class NotConstraint : PrefixConstraint { public NotConstraint(IConstraint baseConstraint) : base(baseConstraint) { descriptionPrefix = "not"; } public override ConstraintResult ApplyTo<TActual>(TActual actual) { ConstraintResult constraintResult = baseConstraint.ApplyTo(actual); return new ConstraintResult(this, constraintResult.ActualValue, !constraintResult.IsSuccess); } } }