public void EmptyValidationTextIsSingleEmpty()
        {
            ValidationText vt = ValidationText.Empty;

            Assert.Equal(1, vt.Count);

            // Calling Count() checks the enumeration returns no results, unlike the Count property.
#pragma warning disable CA1829 // Use Length/Count property instead of Count() when available
            Assert.Equal(1, vt.Count());
#pragma warning restore CA1829 // Use Length/Count property instead of Count() when available
            Assert.Same(string.Empty, vt.Single());
            Assert.Equal(string.Empty, vt.ToSingleLine());
        }