code: def test_shape(self, input_param, input_data, expected_val):
      result = DiffusionLoss(**input_param).forward(**input_data)
      np.testing.assert_allclose(
          result.detach().cpu().numpy(), expected_val, rtol=1e-5
      )
  
file_path: MONAI/tests/test_diffusion_loss.py
imports: from __future__ import annotations
  import unittest
  import numpy
  import torch
  from parameterized import parameterized
  from monai.losses.deform import DiffusionLoss
label_desc: Use image node_id 1 for calling the TestDiffusionLoss obj's underlying member method code with example usage: obj.test_shape(input_param, input_data, expected_val) without return types