code: def test_5(self):
      class X(Structure):
          _fields_ = (("char", c_char * 5),)
  
      x = X(b"#" * 5)
      x.char = b"a\0b\0"
      self.assertEqual(bytes(x), b"a\x00###")
  
file_path: cpython/Lib/test/test_ctypes/test_struct_fields.py
imports: import unittest
  from ctypes import Structure, Union, sizeof, c_char, c_int
  from ._support import CField, Py_TPFLAGS_DISALLOW_INSTANTIATION, Py_TPFLAGS_IMMUTABLETYPE
label_desc: Use image node_id 6 for calling the StructFieldsTestCase obj's underlying member method code with example usage: obj.test_5() without return types