camel_folder_transfer_messages_to(): Provider assumptions?

Hi,

Can I assume anything regarding the "source" and "dest" folders below?

void camel_folder_transfer_messages_to(CamelFolder *source, 
                                       GPtrArray *uids, 
                                       CamelFolder *dest, 
                                       GPtrArray **transferred_uids,
                                       gboolean delete_originals,
                                       CamelException *ex);

It would be natural to expect that both folders are served by the Camel
provider implementing the method and that inter-provider copies/moves of
messages are done with append_message(), but that is not specifically
stated in the documentation.

Anyone care the confirm this assumption?


Thanks,
  jules