fix [] cannot grow issue, array may contain objects of type 'Any'

[appleparan]

fix #10

[wookay]

리베이스 squash 해주시면 감사합니다 https://git-scm.com/book/ko/v1/Git-%EB%8F%84%EA%B5%AC-%ED%9E%88%EC%8A%A4%ED%86%A0%EB%A6%AC-%EB%8B%A8%EC%9E%A5%ED%95%98%EA%B8%B0