Rx.Observable.throw(exception, [scheduler])
Returns an observable sequence that terminates with an exception, using the specified scheduler to send out the single onError message.
Arguments
dueTime(Any): Absolute (specified as a Date object) or relative time (specified as an integer denoting milliseconds) at which to produce the first value.[scheduler=Rx.Scheduler.immediate](Scheduler): Scheduler to send the exceptional termination call on. If not specified, defaults to the immediate scheduler.
Returns
(Observable): The observable sequence that terminates exceptionally with the specified exception object.