code: def test_byte_plus(self):
      self._dll.tf_bb.restype = c_byte
      self._dll.tf_bb.argtypes = (c_byte, c_byte)
      self.assertEqual(self._dll.tf_bb(0, -126), -42)
      self.assertEqual(self.S(), -126)
  
imports: import unittest
  from ctypes import *
  from ctypes.test import need_symbol
  import _ctypes_test
label_desc: Use image node_id 4 for calling the CFunctions obj's underlying member method code with example usage: obj.test_byte_plus() without return types