await writer.end();
Film type: Fujifilm Instax Mini film (sold separately) / Film size: 2 x 3-inches / Weight: 306 grams / Charging method: AA batteries / Companion app: None / Other features: Built-in selfie mirror, film counter
，这一点在雷电模拟器官方版本下载中也有详细论述
// Stateful transform — a generator that wraps the source
def __str__(self):