code: def test_1(self):
      f = dll._testfunc_callback_i_if
      f.restype = ctypes.c_int
      f.argtypes = [ctypes.c_int, MyCallback]
  
      def callback(value):
          return value
  
      self.assertEqual(sys.getrefcount(callback), 2)
      cb = MyCallback(callback)
  
      self.assertGreater(sys.getrefcount(callback), 2)
      result = f(-10, cb)
      self.assertEqual(result, -18)
      cb = None
  
      gc.collect()
  
      self.assertEqual(sys.getrefcount(callback), 2)
  
file_path: cpython/Lib/test/test_ctypes/test_refcounts.py
imports: import _ctypes_test
  import ctypes
  import gc
  import sys
  import unittest
  from test import support
label_desc: Use image node_id 1 for calling the RefcountTestCase obj's underlying member method code with example usage: obj.test_1() and returns: value