public void ConvertToXml_ForEmptyString_ShouldReturnHeader()
        {
            // Arrange
            var input  = string.Empty;
            var output = @"<?xml version=""1.0"" encoding=""utf-16""?>
<text />";

            // Act
            var result = _target.ConvertToXml(input);

            // Assert
            Assert.AreEqual(output, result.Value);
        }