code: def test_sqrt(self):
      lib.my_sqrt.argtypes = (c_double,)
      lib.my_sqrt.restype = c_double
      self.assertEqual(lib.my_sqrt(4.0), 2.0)
      self.assertEqual(lib.my_sqrt(2.0), math.sqrt(2.0))
  
file_path: cpython/Lib/test/test_ctypes/test_libc.py
imports: import _ctypes_test
  import math
  import unittest
  from ctypes import CDLL, CFUNCTYPE, POINTER, create_string_buffer, sizeof, c_void_p, c_char, c_int, c_double, c_size_t
label_desc: Use image node_id 1 for calling the LibTest obj's underlying member method code with example usage: obj.test_sqrt() without return types