エラー処理

This segment should take about 1 hour and 5 minutes. It contains:

SlideDuration
パニック(panic)3 minutes
Result5 minutes
Try演算子5 minutes
Try変換5 minutes
Errorトレイト5 minutes
thiserror5 minutes
anyhow5 minutes
演習: Result を使用した書き換え30 minutes