code: def test_self_inside_function_w_multiple_closures(self):
      # Test when a function contins multiple closures
  
      class Foo:
          def method(self):
              class Baz:
                  def baz_str(self):
                      return "Baz"
  
              baz = Baz()
              x = "x"
  
              class Bar:
                  def bar_str(self):
                      return x + "Bar"
  
                  def method(self):
                      def fn():
                          return self.bar_str() + baz.baz_str()
  
                      return fn
  
              bar = Bar()
              return bar.method()
  
      foo = Foo()
      fn = foo.method()
      # cells for `self.bar_str()`, `baz.baz_str()`
      self.assertLen(fn.__closure__, 2)
  
      func_map = free_vars_detect._detect_function_free_vars(fn)
      self.assertLen(func_map.keys(), 2)
  
      self.assertIn("fn", func_map.keys())
      free_vars = get_var_name(func_map["fn"])
      self.assertSequenceEqual(
          free_vars, ["baz", "self", "self.bar_str"]
      )
  
      self.assertIn("Bar.bar_str", func_map.keys())
      free_vars = get_var_name(func_map["Bar.bar_str"])
      self.assertSequenceEqual(free_vars, ["x"])
  
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 20 for calling the FreeVarDetectionTest obj's underlying member method code with example usage: obj.test_self_inside_function_w_multiple_closures() and returns: bar, str, unknown, fn, unknown