code: def test_forward(self):
      fce_head = FCEHead(in_channels=10, fourier_degree=5)
      data = [
          torch.randn(2, 10, 20, 20),
          torch.randn(2, 10, 30, 30),
          torch.randn(2, 10, 40, 40),
      ]
      results = fce_head(data)
      self.assertIn("cls_res", results[0])
      self.assertIn("reg_res", results[0])
      self.assertEqual(results[0]["cls_res"].shape, (2, 4, 20, 20))
      self.assertEqual(results[0]["reg_res"].shape, (2, 22, 20, 20))
      self.assertEqual(results[1]["cls_res"].shape, (2, 4, 30, 30))
      self.assertEqual(results[1]["reg_res"].shape, (2, 22, 30, 30))
      self.assertEqual(results[2]["cls_res"].shape, (2, 4, 40, 40))
      self.assertEqual(results[2]["reg_res"].shape, (2, 22, 40, 40))
  
imports: from unittest import TestCase
  import torch
  from mmocr.models.textdet.heads import FCEHead
label_desc: Use image node_id 2 for calling the TestFCEHead obj's underlying member method code with example usage: obj.test_forward() without return types