code: def test_nested_if_temporarily_undefined_return_illegal(self, c1, c2):
      c1 = tf.constant(c1)
      c2 = tf.constant(c2)
      with self.assertRaisesRegex(
          ValueError, "must also have a return"
      ):
          tf.function(nested_if_temporarily_undefined_return)(c1, c2)
  
imports: import itertools
  import re
  from absl.testing import parameterized
  import tensorflow
  from tensorflow.python.autograph.tests import reference_test_base
label_desc: Use image node_id 10 for calling the ReferenceTest obj's underlying member method code with example usage: obj.test_nested_if_temporarily_undefined_return_illegal(c1, c2) without return types