code: def test_input_warnings(self):
      chn_input = torch.ones((1, 1, 3))
      chn_target = torch.ones((1, 1, 3))
      with self.assertWarns(Warning):
          loss = MaskedDiceLoss(include_background=False)
          loss.forward(chn_input, chn_target)
      with self.assertWarns(Warning):
          loss = MaskedDiceLoss(softmax=True)
          loss.forward(chn_input, chn_target)
      with self.assertWarns(Warning):
          loss = MaskedDiceLoss(to_onehot_y=True)
          loss.forward(chn_input, chn_target)
  
file_path: MONAI/tests/test_masked_dice_loss.py
imports: from __future__ import annotations
  import unittest
  import numpy
  import torch
  from parameterized import parameterized
  from monai.losses import MaskedDiceLoss
label_desc: Use image node_id 4 for calling the TestDiceLoss obj's underlying member method code with example usage: obj.test_input_warnings() without return types