code: def test_struct(self):
      class X(Structure):
          _fields_ = [("a", c_char * 3)]
  
      x = X(b"abc")
      self.assertRaises(TypeError, X, "abc")
      self.assertEqual(x.a, b"abc")
      self.assertEqual(type(x.a), bytes)
  
file_path: cpython/Lib/test/test_ctypes/test_bytes.py
imports: import sys
  import unittest
  from _ctypes import _SimpleCData
  from ctypes import Structure, c_char, c_char_p, c_wchar, c_wchar_p
label_desc: Use image node_id 5 for calling the BytesTest obj's underlying member method code with example usage: obj.test_struct() without return types