docstr: Test PyUnicode_Concat()
docstr_tok: ["Test","PyUnicode_Concat","(",")"]
code: def test_concat(self):
      """Test PyUnicode_Concat()"""
      from _testcapi import unicode_concat as concat
  
      self.assertEqual(concat("abc", "def"), "abcdef")
      self.assertEqual(concat("abc", "где"), "abcгде")
      self.assertEqual(concat("абв", "def"), "абвdef")
      self.assertEqual(concat("абв", "где"), "абвгде")
      self.assertEqual(concat("a\0b", "c\0d"), "a\0bc\0d")
  
      self.assertRaises(TypeError, concat, b"abc", "def")
      self.assertRaises(TypeError, concat, "abc", b"def")
      self.assertRaises(TypeError, concat, b"abc", b"def")
      self.assertRaises(TypeError, concat, [], "def")
      self.assertRaises(TypeError, concat, "abc", [])
      self.assertRaises(TypeError, concat, [], [])
  
imports: import unittest
  import sys
  from test import support
  from test.support import import_helper
label_desc: Use image node_id 27 for calling the CAPITest obj's underlying member method code with example usage: obj.test_concat() without return types