code: def test_invalid_character(self):
      self._test(
          b"dm\x01k===", b"vi", [errors.InvalidBase64CharactersDefect]
      )
  
imports: import unittest
  from email import _encoded_words
  from email import errors
  from test.test_email import TestEmailBase
label_desc: Use image node_id 4 for calling the TestDecodeB obj's underlying member method code with example usage: obj.test_invalid_character() without return types