code: def test_simple_function(self):
      def fn(a, b):
          return a + b
  
      self.assertEqual(("a", "b"), function_utils.fn_args(fn))
  
imports: import functools
  from tensorflow.python.platform import test
  from tensorflow.python.util import function_utils
label_desc: Use image node_id 1 for calling the FnArgsTest obj's underlying member method code with example usage: obj.test_simple_function() and returns: unknown