def METHOD_NAME(self):
    """
    ests the case when embedding fails for some words that are tried to be
    inserted - insert only successfully embedded words
    """
    tree, skipped = self.handler.generate(['1', '2', '3'])
    self.assertEqual(skipped, 0)
    new_tree, skipped = self.handler.insert(tree, ['4', '5'])
    self.assertDictEqual(new_tree, {'1': {'2': {'4': {}}, '3': {}}})
    self.assertEqual(skipped, 1)