def test_correction_by_substituting(self):
        collection_of_words = set(['bat', 'banana', 'shoe', 'dog'])
        word_set_helper = WordSetHelper(collection_of_words)
        correction = word_set_helper._find_words_by_substituting('dag')

        self.assertEqual(correction, ['dog'])
    def test_correction_by_searching(self):
        collection_of_words = set(['bat', 'banana', 'shoe', 'dog'])
        word_set_helper = WordSetHelper(collection_of_words)
        correction = word_set_helper._find_closest_words_by_searching('ban')

        self.assertEqual(correction, ['banana'])
    def test_get_alternative_words_limited(self):
        collection_of_words = set(['bat', 'banana', 'shoe', 'dog'])
        word_set_helper = WordSetHelper(collection_of_words)
        correction = word_set_helper.get_alternative_words('ban', 1)

        self.assertEqual(correction, ['bat'])