Removing the default_pool from a Virtual Server.

Ok, so I can set__default_pool_name using the syntax below (C), but how can I set the default_pool to None?

 

 

m_interfaces.LocalLBVirtualServer.set_default_pool_name(new string[] { vipName }, new string[] { vipPool });

 

 

I don't see any methods to 'remove_default_pool' or the like.