code: def test_single(self):
      targets = torch.tensor([[4]])
      one_hot_target = convert_to_one_hot(targets, 5)
      self.assertTrue(
          torch.allclose(
              one_hot_target, torch.tensor([[0, 0, 0, 0, 1]])
          )
      )
  
imports: import unittest
  import torch
  from classy_vision.generic.util import convert_to_one_hot
label_desc: Use image node_id 1 for calling the TestUtils obj's underlying member method code with example usage: obj.test_single() without return types