code: def test_read_undefined(self):
      with self.assertRaisesRegex(
          UnboundLocalError, "used before assignment"
      ):
          variables.ld(variables.Undefined("a"))
  
file_path: tensorflow-upstream/tensorflow/python/autograph/operators/variables_test.py
imports: from tensorflow.python.autograph.operators import variables
  from tensorflow.python.platform import test
label_desc: Use image node_id 4 for calling the SpecialValuesTest obj's underlying member method code with example usage: obj.test_read_undefined() without return types