def callback(track_transfer_batch, user_param1, ...)
Emitted when the batch is started. This will be after all previous batches have finished, which is not necessarily when rb_track_transfer_manager_start_batch is called.
track_transfer_batch : |
instance of RB.TrackTransferBatch that is emitting the signal |
user_param1 : |
first user parameter (if any) specified with the connect() method |
... : |
additional user parameters (if any) |