public static IComparisonResult Includes <T>(this IEnumerable <T> collection, T obj) => ComparisonResult.FromBoolean(collection.Any(c => c?.Equals(obj) == true), "Collection does not contain the specified value");
public static IComparisonResult Includes <T>(this IEnumerable <T> collection1, IEnumerable <T>?collection2) => Test.Collection(collection1) ?? Test.Collection(collection2) ?? ComparisonResult.FromBoolean(collection2?.All(c => collection1.Contains(c)), "First collection does not contain all elements of second collection");