**Please copy the following template [here](https://github.com/ReactiveX/RxSwift/issues/new) and fill in the missing fields so we can help you as soon as possible.** ``` *Short description of missing functionality*: E.g. I want this library to implement xxx operator. *Short code example of how you would like to use the API*: code goes here *The reason why I need this functionality*: E.g. I was trying to .... *Code I have right now*: code snippet that demonstrates how you've attempted to solve the problem ```