code: def setUp(self) -> None:
      self.loss = MaskedSquareDiceLoss()
      self.pred = torch.FloatTensor([0, 1, 0, 1])
      self.gt = torch.ones_like(self.pred)
      self.mask = torch.FloatTensor([1, 1, 0, 1])
  
file_path: mmocr/tests/test_models/test_common/test_losses/test_dice_loss.py
imports: from unittest import TestCase
  import torch
  from mmocr.models.common.losses import MaskedDiceLoss, MaskedSquareDiceLoss
label_desc: Use image node_id 1 for calling the TestMaskedSquareDiceLoss obj's underlying member method code with example usage: obj.setUp() without return types