new_contents: import unittest
  from lib import mnemonic
  from lib import old_mnemonic
  
  class Test_NewMnemonic(unittest.TestCase):
  
      def test_prepare_seed(self):
          seed = 'foo BAR Baz'
          self.assertEquals(mnemonic.prepare_seed(seed), 'foo bar baz')
  
      def test_to_seed(self):
          seed = mnemonic.Mnemonic.mnemonic_to_seed(mnemonic='foobar', passphrase='none')
          self.assertEquals(seed.encode('hex'),
                            '741b72fd15effece6bfe5a26a52184f66811bd2be363190e07a42cca442b1a5b'
                            'b22b3ad0eb338197287e6d314866c7fba863ac65d3f156087a5052ebc7157fce')
  
      def test_random_seeds(self):
          iters = 10
          m = mnemonic.Mnemonic(lang='en')
          for _ in range(iters):
              seed = m.make_seed()
              self.assertTrue(m.check_seed(seed, custom_entropy=1))
              i = m.mnemonic_decode(seed)
              self.assertEquals(m.mnemonic_encode(i), seed)
  
  
  class Test_OldMnemonic(unittest.TestCase):
  
      def test(self):
          seed = '8edad31a95e7d59f8837667510d75a4d'
          result = old_mnemonic.mn_encode(seed)
          words = 'hardly point goal hallway patience key stone difference ready caught listen fact'
          self.assertEquals(result, words.split())
          self.assertEquals(old_mnemonic.mn_decode(result), seed)
  
subject: add tests for mnemonics