public static void IfCollectionContainsNull <T>( [CanBeNull, AssertionCondition(AssertionConditionType.IS_NOT_NULL)] IEnumerable <T> collection, [NotNull][System.Diagnostics.CodeAnalysis.NotNull] string collectionName ) where T : class { Fail.RequiresCollectionName(collectionName); if (collection == null) { throw Fail.Because(Violation.WhenCollectionIsNull(collectionName)); } if (collection.Contains(null)) { throw Fail.Because(Violation.WhenCollectionContainsNull(collectionName)); } }