Update dnaflash.py

dnaflash.py

@@ -13,6 +13,9 @@ import torch.utils.checkpoint
 from torch import nn, Tensor
 from torch.nn import BCEWithLogitsLoss, CrossEntropyLoss, MSELoss
 
+from typing import Optional, Tuple, Union, Any
+
+
 # helper functions
 
 def exists(val):