added pretrainer class to hyperparams.yaml

hyperparams.yaml

@@ -172,3 +172,9 @@ checkpointer: !new:speechbrain.utils.checkpoints.Checkpointer
     lr_scheduler: *id007
 train_logger: !new:speechbrain.utils.train_logger.FileTrainLogger
   save_file: results/sepformer-whamr/1234/train_log.txt
+
+pretrainer: !new:speechbrain.utils.parameter_transfer.Pretrainer
+   loadables:
+      masknet: !ref <MaskNet>
+      encoder: !ref <Encoder>
+      decoder: !ref <Decoder>