dataclass:
Person(name='John', age='40', musics=[{'name': 'Imagine'}])
b'{"name":"John","age":"40","musics":[{"name":"Imagine"}]}'

TypedDict:
{'name': 'John', 'musics': [{'name': 'Imagine'}], 'age': '40'}
b'{"name":"John","musics":[{"name":"Imagine"}],"age":"40"}'
