public void AddRandomValueSource_ThrowsIfPrefixNull()
        {
            // Arrange
            string prefix = null;

            // Act and Assert
            var ex = Assert.Throws <ArgumentException>(() => RandomValueExtensions.AddRandomValueSource(new ConfigurationBuilder(), prefix));
        }
        public void AddRandomValueSource_ThrowsIfConfigBuilderNull()
        {
            // Arrange
            IConfigurationBuilder configurationBuilder = null;

            // Act and Assert
            var ex = Assert.Throws <ArgumentNullException>(() => RandomValueExtensions.AddRandomValueSource(configurationBuilder));
        }