private void Validate_IsProperSupersetOf(PooledSet <T> set, Span <T> span) { bool isProperSuperset = true; bool setContainsElementsNotInEnumerable = false; IEqualityComparer <T> comparer = set.Comparer; foreach (T value in span) { if (!set.Contains(value)) { isProperSuperset = false; break; } } foreach (T value in set) { if (!SpanContains(span, value, comparer)) { setContainsElementsNotInEnumerable = true; break; } } isProperSuperset = isProperSuperset && setContainsElementsNotInEnumerable; Assert.Equal(isProperSuperset, set.IsProperSupersetOf(span)); }