class_docstr: Overall loss function of the third training phase of the DSR model.
  
  The loss consists of a focal loss between the computed segmentation mask and the ground truth mask.
code: def __init__(self) -> None:
      super().__init__()
  
      self.focal_loss = FocalLoss(alpha=1, reduction="mean")
  
file_path: anomalib/src/anomalib/models/dsr/loss.py
imports: from kornia.losses import FocalLoss
  from torch import Tensor, nn
label_desc: Use image node_id 1 to create a new DsrThirdStageLoss object from inherited base classes: nn with example: obj = DsrThirdStageLoss()