namespace NUnit.Framework.Constraints { public abstract class ComparisonAdapter { public static ComparisonAdapter Default { get; } public static ComparisonAdapter For(IComparer comparer); public static ComparisonAdapter For<[Nullable(2)] T>(IComparer<T> comparer); public static ComparisonAdapter For<[Nullable(2)] T>(Comparison<T> comparer); public abstract int Compare(object expected, object actual); protected ComparisonAdapter(); } }