public void FailsWithInvalidTimeSpanValue()
            {
                // Arrange
                var xmlAttribute = new StubXmlAttribute("tmax", "unknown-value");

                // Act
                TimeSpan actualTimeSpan = xmlAttribute.AsTimeSpan();

                // Assert
                Assert.Equal(default(TimeSpan), actualTimeSpan);
            }
            public void SucceedsWithValidTimeSpanValue()
            {
                // Arrange
                var xmlAttribute = new StubXmlAttribute("tmin", "0:00:01");

                // Act
                TimeSpan actualTimeSpan = xmlAttribute.AsTimeSpan();

                // Assert
                Assert.Equal(TimeSpan.FromSeconds(1), actualTimeSpan);
            }