docstr: Test PyUnicode_AsASCIIString()
docstr_tok: ["Test","PyUnicode_AsASCIIString","(",")"]
code: def test_asasciistring(self):
      """Test PyUnicode_AsASCIIString()"""
      asasciistring = _testcapi.unicode_asasciistring
  
      self.assertEqual(asasciistring("abc"), b"abc")
  
      self.assertRaises(UnicodeEncodeError, asasciistring, "\x80")
      self.assertRaises(TypeError, asasciistring, b"abc")
      self.assertRaises(TypeError, asasciistring, [])
  
imports: import unittest
  import sys
  from test.support import import_helper
label_desc: Use image node_id 16 for calling the CAPITest obj's underlying member method code with example usage: obj.test_asasciistring() without return types