https://developer.apple.com/library/content/documentation/Swift/Conceptual/Swift_Programming_Language/ControlFlow.html#//apple_ref/doc/uid/TP40014097-CH9-ID141

7:00 AM

hogeFugaSubscription: do { ... }

7:00 AM

こう書けるのかラベル付きdo

7:01 AM

良さそう。