code: def test_iter_copy(self):
      callback = "test"
      clist = CallbackList([callback])
      cpy = clist.__copy__()
      self.assertTrue(cpy.callback_list[0] == "test")
      self.assertTrue(cpy is not clist)
      cpy = clist.copy()
      self.assertTrue(cpy.callback_list[0] == "test")
      self.assertTrue(cpy is not clist)
      for cback in clist:
          self.assertTrue(cback == "test")
  
file_path: torchbearer/tests/callbacks/test_callbacks.py
imports: import warnings
  from unittest import TestCase
  from mock import MagicMock, Mock
  import torchbearer
  from torchbearer.callbacks import CallbackList, Tqdm, TensorBoard
label_desc: Use image node_id 6 for calling the TestCallbackList obj's underlying member method code with example usage: obj.test_iter_copy() without return types