docstr: Test PyUnicode_AsUCS4Copy()
docstr_tok: ["Test","PyUnicode_AsUCS4Copy","(",")"]
code: def test_asucs4copy(self):
      """Test PyUnicode_AsUCS4Copy()"""
      from _testcapi import unicode_asucs4copy as asucs4copy
  
      for s in [
          "abc",
          "\xa1\xa2",
          "\u4f60\u597d",
          "a\U0001f600",
          "a\ud800b\udfffc",
          "\ud834\udd1e",
      ]:
          self.assertEqual(asucs4copy(s), s + "\0")
          s = "\0".join([s, s])
          self.assertEqual(asucs4copy(s), s + "\0")
  
imports: import unittest
  import sys
  from test import support
  from test.support import import_helper
label_desc: Use image node_id 21 for calling the CAPITest obj's underlying member method code with example usage: obj.test_asucs4copy() without return types