Rx.Observable.prototype.finally(action)

Invokes a specified action after the source observable sequence terminates gracefully or exceptionally.

Arguments

1. predicate (Function): A function to test each source element for a condition; The callback is called with the following information:
   1. the value of the element
   2. the index of the element
   3. the Observable object being subscribed
2. [thisArg] (Any): Object to use as this when executing the predicate.

Returns

(Observable): An observable sequence that contains elements from the input sequence that satisfy the condition.

Example