def get_next_id(self):
        try:
            query = {'_id': 'last_id'}
            update = {'$inc': {'id': 1}}
            fn = self.db.internal.find_and_modify
            row = fn(query, update, upsert=True, new=True)
        except Exception as e:
            raise DatabaseException(e)
        return row['id']
def test_ccode_boolean():
    assert ccode(x & y) == "x && y"
    assert ccode(x | y) == "x || y"
    assert ccode(~x) == "!x"
    assert ccode(x & y & z) == "x && y && z"
    assert ccode(x | y | z) == "x || y || z"
    assert ccode((x & y) | z) == "z || x && y"
    assert ccode((x | y) & z) == "z && (x || y)"