code: def test_while_change(self):
      def test_fn(x, z: int):
          while z > 0:
              x = x.cuda()
              z = 0
          return x
  
      self.assert_device_equal(test_fn, [self.cpu, None], None)
      self.assert_device_equal(test_fn, [self.cuda, None], self.cuda)
      self.assert_device_equal(test_fn, [None, None], None)
  
imports: from itertools import product
  import unittest
  import torch
  from torch.testing._internal.common_utils import TEST_CUDA
  from torch.testing._internal.jit_utils import JitTestCase
  from torch.jit._passes._property_propagation import apply_input_props_using_example
label_desc: Use image node_id 19 for calling the TestDeviceAnalysis obj's underlying member method code with example usage: obj.test_while_change() and returns: x