public static void AddStringProperty(
this ConfigurationPropertyCollection properties,
string name,
ConfigurationValidatorBase validator,
ConfigurationPropertyOptions options = ConfigurationPropertyOptions.IsRequired)
{
// http://stackoverflow.com/questions/3744953/why-does-configurationvalidator-validate-the-default-value-of-a-configurationprop
properties.Add(new ConfigurationProperty(
name: name,
type: typeof(string),
defaultValue: null,
typeConverter: null,
validator: validator,
options: options));
}