これ必ず↓の順序で呼び出されるってこと？
Task.detached { print(Thread.current) print(await bankAccount.deposit(100)) // 1 print(await bankAccount.getInterest(with: 0.5)) // 3 } Task { print(Thread.current) print(await bankAccount.deposit(100)) // 2 print(await bankAccount.getInterest(with: 0.5)) // 4 }