public static void ToXml(this IExpression expression, XmlTextWriter writer)
{
if (null == expression)
{
throw new ArgumentNullException("expression");
}
if (null == writer)
{
throw new ArgumentNullException("writer");
}
Configuration config = new Configuration();
IConfigurationElement configElement = config.AddSection("expression extensions").AddElement("expression");
expression.ToConfiguration(configElement);
configElement.WriteXml(writer);
}