code: def test_bytes(self):
      with dbm.ndbm.open(self.filename, "c") as db:
          db[b"bytes key \xbd"] = b"bytes value \xbd"
      with dbm.ndbm.open(self.filename, "r") as db:
          self.assertEqual(list(db.keys()), [b"bytes key \xbd"])
          self.assertTrue(b"bytes key \xbd" in db)
          self.assertEqual(db[b"bytes key \xbd"], b"bytes value \xbd")
  
imports: from test.support import import_helper
  from test.support import os_helper
  import os
  import unittest
  import dbm.ndbm
  from dbm.ndbm import error
label_desc: Use image node_id 7 for calling the DbmTestCase obj's underlying member method code with example usage: obj.test_bytes() without return types