property TransparentProxy: TIdCustomTransparentProxy;

TransparentProxy is a TIdCustomTransparentProxy property that represents the proxy server to use for the IOHandler connection. 

Reading the value in TransparentProxy will ensure that a TIdSocksInfo instance has been created for the property. 

Assigning a new TIdCustomTransparentProxy to the property ensures that an existing value in the property is freed, an that the correct class type is used for creating the new object instance for the property. 

TransparentProxy is freed (when assigned) in Destroy.