public StorageGroupElement()
{
_storageGroup = new DoubleCheckedLockingContainer <StorageGroupAttribute> (
delegate { return((StorageGroupAttribute)Activator.CreateInstance(StorageGroupType)); });
_storageGroupTypeProperty = TypeElement <StorageGroupAttribute> .CreateTypeProperty(null);
_storageProviderNameProperty = new ConfigurationProperty(
"provider",
typeof(string),
null,
ConfigurationPropertyOptions.IsRequired);
_properties.Add(_storageGroupTypeProperty);
_properties.Add(_storageProviderNameProperty);
}