code: def test_from_dll(self):
      dll = CDLL(_ctypes_test.__file__)
      # _CFuncPtr instances are now callable with a tuple argument
      # which denotes a function name and a dll:
      strchr = CFUNCTYPE(c_char_p, c_char_p, c_char)(("my_strchr", dll))
      self.assertTrue(strchr(b"abcdef", b"b"), "bcdef")
      self.assertEqual(strchr(b"abcdef", b"x"), None)
      self.assertRaises(ArgumentError, strchr, b"abcdef", 3.0)
      self.assertRaises(TypeError, strchr, b"abcdef")
  
file_path: cpython/Lib/test/test_ctypes/test_returnfuncptrs.py
imports: import _ctypes_test
  import unittest
  from ctypes import CDLL, CFUNCTYPE, ArgumentError, c_char_p, c_void_p, c_char
label_desc: Use image node_id 3 for calling the ReturnFuncPtrTestCase obj's underlying member method code with example usage: obj.test_from_dll() without return types