code: def test_no_free_var(self):
      def f(x):
          return x + 1
  
      txt = free_vars_detect.generate_free_var_logging(f)
      self.assertIsNone(txt)
  
imports: import functools
  import unittest
  from absl.testing import parameterized
  import numpy
  from tensorflow.core.function.capture import free_vars_detect
  from tensorflow.python.util import tf_decorator
label_desc: Use image node_id 5 for calling the GenerateLoggingTest obj's underlying member method code with example usage: obj.test_no_free_var() and returns: unknown