code: def test_key_repr(self):
      key = torchbearer.state_key("repr_test")
      self.assertEqual(str(key), "repr_test")
      self.assertEqual(repr(key), "repr_test")
  
imports: import unittest
  import warnings
  import torchbearer
  from torchbearer.state import State
label_desc: Use image node_id 3 for calling the TestStateKey obj's underlying member method code with example usage: obj.test_key_repr() without return types