Returns an idle Promise instance that is already resolved with the given value. If the value passed is
a promise then that promise is returned instead of creating a new asynchronous promise instance.
If a new instance is returned then any chained operations will execute asynchronously using the
requestIdleCallback API (if available) with the optional provided timeout value to schedule when
the chained items will be executed. (eg. then(); finally()).
Returns an idle Promise instance that is already resolved with the given value. If the value passed is a promise then that promise is returned instead of creating a new asynchronous promise instance. If a new instance is returned then any chained operations will execute asynchronously using the
requestIdleCallbackAPI (if available) with the optional provided timeout value to schedule when the chained items will be executed. (eg.then();finally()).