How to use the smt.phrase.phrase_extract.phrase_extract function in smt

'er',
                     'im',
                     'haus',
                     'bleibt')),
                   (('that',), (',', 'dass')),
                   (('that',), ('dass',)),
                   (('that', 'he'), (',', 'dass', 'er')),
                   (('that', 'he'), ('dass', 'er')),
                   (('that', 'he', 'will', 'stay', 'in', 'the', 'house'),
                    (',', 'dass', 'er', 'im', 'haus', 'bleibt')),
                   (('that', 'he', 'will', 'stay', 'in', 'the', 'house'),
                    ('dass', 'er', 'im', 'haus', 'bleibt')),
                   (('will', 'stay'), ('bleibt',)),
                   (('will', 'stay', 'in', 'the', 'house'),
                    ('im', 'haus', 'bleibt'))])
        self.assertEqual(phrase_extract(es, fs, alignment), ans)

        # another test
        es, fs = ("私 は 先生 です".split(), "I am a teacher".split())
        sentenses = [("僕 は 男 です", "I am a man"),
                     ("私 は 女 です", "I am a girl"),
                     ("私 は 先生 です", "I am a teacher"),
                     ("彼女 は 先生 です", "She is a teacher"),
                     ("彼 は 先生 です", "He is a teacher"),
                     ]
        corpus = mkcorpus(sentenses)
        alignment = symmetrization(es, fs, corpus)
        ans = set([(('\xe3\x81\xaf',
                     '\xe5\x85\x88\xe7\x94\x9f',
                     '\xe3\x81\xa7\xe3\x81\x99'),
                    ('a', 'teacher')),
                   (('\xe5\x85\x88\xe7\x94\x9f',), ('teacher',)),

("彼 は 先生 です", "He is a teacher"),
                     ]
        corpus = mkcorpus(sentenses)
        alignment = symmetrization(es, fs, corpus)
        ans = set([(('\xe3\x81\xaf',
                     '\xe5\x85\x88\xe7\x94\x9f',
                     '\xe3\x81\xa7\xe3\x81\x99'),
                    ('a', 'teacher')),
                   (('\xe5\x85\x88\xe7\x94\x9f',), ('teacher',)),
                   (('\xe7\xa7\x81',), ('I', 'am')),
                   (('\xe7\xa7\x81',
                     '\xe3\x81\xaf',
                     '\xe5\x85\x88\xe7\x94\x9f',
                     '\xe3\x81\xa7\xe3\x81\x99'),
                    ('I', 'am', 'a', 'teacher'))])
        self.assertEqual(phrase_extract(es, fs, alignment), ans)

def db_phrase_extract(lang1, lang2,
                      lang1method=lambda x: x,
                      lang2method=lambda x: x,
                      init_val=1.0e-10,
                      db="sqlite:///:memory:"):
    lang1s = lang1method(lang1).split()
    lang2s = lang1method(lang2).split()
    alignment = _db_symmetrization(lang1s, lang2s,
                                   init_val=init_val,
                                   db=db)
    return phrase_extract.phrase_extract(lang1s, lang2s, alignment)