Interface Wakeable

packages/shared/ReactTypes.js:99–101

// The subset of a Thenable required by things thrown by Suspense.
// This doesn't require a value to be passed to either handler.
export interface Wakeable {
  then(onFulfill: () => mixed, onReject: () => mixed): void | Wakeable;
}

// The subset of a Promise that React APIs rely on. This resolves a value.
// This doesn't require a return value neither from the handler nor the