keen/js/deferred

Source
deferred[t] record (has private fields)
Type that is useful for detailing with JS asynchronous events. Create a deferred and set it up so that it will resolve once. Then await the deferred which blocks until resolve is called.
new[t] t deferred() js
await[t] t(a t deferred) unsafe, js
This will hang forever if 'resolve' is never called.
resolve[t] void(a t deferred, value t) unsafe, js
Provides a value to whatever is awaiting this deferred. It's safe to call this before the await.