code: def test_c_wchar(self):
      result = self.fail_fields(("a", c_wchar, 1))
      self.assertEqual(
          result, (TypeError, "bit fields not allowed for type c_wchar")
      )
  
imports: import _ctypes_test
  import os
  import unittest
  from ctypes import CDLL, Structure, sizeof, POINTER, byref, alignment, LittleEndianStructure, BigEndianStructure, c_byte, c_ubyte, c_char, c_char_p, c_void_p, c_wchar, c_uint32, c_uint64, c_short, c_ushort, c_int, c_uint, c_long, c_ulong, c_longlong, c_ulonglong
  from test import support
label_desc: Use image node_id 7 for calling the BitFieldTest obj's underlying member method code with example usage: obj.test_c_wchar() without return types